diff --git a/run.json b/run.json
index 0f0b3581f..c25aebe55 100644
--- a/run.json
+++ b/run.json
@@ -505,7 +505,7 @@
     "kind": "running"
   },
   "status_updated_at": "2026-07-09T23:18:01.698576530Z",
-  "last_event_at": "2026-07-09T23:51:33.428120642Z",
+  "last_event_at": "2026-07-09T23:51:37.406580876Z",
   "pending_control": null,
   "checkpoints": [
     {
@@ -1074,9 +1074,9 @@
       }
     },
     {
-      "seq": 0,
+      "seq": 581,
       "checkpoint": {
-        "timestamp": "2026-07-09T23:51:33.523678220Z",
+        "timestamp": "2026-07-09T23:51:37.403194534Z",
         "current_node": "simplify_gpt",
         "completed_nodes": [
           "start",
@@ -1089,19 +1089,203 @@
         ],
         "node_retries": {},
         "context_values": {
+          "thread.preflight_compile.current_node": "preflight_lint",
+          "last_stage": "simplify_fable",
+          "internal.retry_count.simplify_fable": 0,
+          "internal.retry_count.preflight_lint": 0,
+          "internal.retry_count.preflight_compile": 0,
+          "internal.retry_count.implement": 0,
+          "graph.model_stylesheet": "\n            * { model: claude-opus-4-8; }\n        ",
+          "graph.goal": "# Demote `server.integrations.slack.default_channel` to a plain literal string\n\n**Self-contained implementation plan.** Everything needed to implement this is\nin this file plus the repository. Independent — no preconditions; can land\nanytime. (It must land before a separate, later effort freezes a registry of\nconfig-field kinds, but nothing in this plan depends on that.)\n\n> **Token notation.** Interpolation tokens are written in this file without\n> their enclosing double curly braces, so the file is safe to pass directly as\n> a workflow goal (the goal templater would otherwise try to expand them).\n> Read `env.NAME`, `vars.NAME`, `secrets.NAME` as the double-curly-brace token\n> form used in the codebase, and write the real double-brace syntax in the\n> code, tests, and docs you produce.\n\n## Context and goal\n\n`server.integrations.slack.default_channel` is the last server-defined config\nfield still typed `InterpString`. Every other server-scope field was demoted\nto a plain literal under the project's rule that interpolation belongs to\nfields resolved with run context — server-startup consumption is served\nnatively by shells/compose/systemd, and a token there just ferries an env var\nacross a process boundary.\n\nThis field is exactly that case:\n\n- It was **born `Option<String>`** (2026-03-05, in the original Slack\n  integration crate; adopted into server settings 2026-04-07) and was\n  documented from the start with literal examples only. The v2 settings\n  schema typed it `InterpString` (2026-04-09) and wired env resolution the\n  same day as part of that schema's uniform staged design — not a\n  field-specific feature, and never requested or documented as interpolable.\n  The one place env-interpolated Slack channels ARE a deliberate, documented\n  feature is run-scope notification routes (added 2026-05-23) — a surface\n  this change does not touch. The uniform-staging capability was superseded\n  by the later interpolation-taxonomy decision that startup-consumed server\n  fields stay literal, under which every comparable server field was already\n  demoted.\n- It resolves **once, at server startup, env-only** — no secrets, no vars,\n  and never re-resolved at message-send time.\n- **No documentation ever advertised interpolation** on it; every doc example\n  is a plain literal channel name.\n- The **run-scope interpolating surface already exists** and is the\n  user-facing one: `run.notifications.<route>.slack.channel` and\n  `run.interviews.slack.channel` are `InterpString` with variable\n  substitution at run creation. The server field is only the zero-config\n  fallback destination for interview prompts.\n- Product direction reinforces it: in hosted deployments users have no access\n  to server env at all (their surface is variables and secrets at run scope),\n  and a future chat-integration plugin system should inherit a simple literal\n  field, not a special-case interpolating one.\n\n**Goal:** change the field to a plain `Option<String>` end-to-end, drop the\nstartup resolution, and emit the standard demoted-field warning when a\nleftover token-shaped value is found — matching how the earlier server-field\ndemotions were shipped.\n\nDesign rules (fixed):\n\n- **Keep the field** as the operator's literal fallback. Do not remove it or\n  relocate it; run scope already covers per-run needs.\n- **Wire-invisible.** `InterpString` serializes as its raw source string, so\n  the stored/wire JSON shape is unchanged by this demote. The OpenAPI schema\n  already models the field as a plain string — no spec change.\n- **Warn, don't break.** A value still containing a token-shaped span (double\n  curly braces) parses fine as a literal; emit the existing demoted-field\n  warning at resolve time so the ~3 months of nightly builds where an env\n  token would have resolved get a loud, non-fatal migration signal.\n\n## Verified current state (as of main `d5dcd1179`, 2026-07-09 — re-verify before starting; line numbers are anchors, not gospel)\n\n- Type: `lib/crates/fabro-types/src/settings/server.rs:258-271` —\n  `SlackIntegrationSettings { enabled: bool, default_channel:\n  Option<InterpString> }`.\n- Config layer: `lib/crates/fabro-config/src/layers/server.rs:237` —\n  `default_channel: Option<InterpString>`.\n- Resolve copy-through: `lib/crates/fabro-config/src/resolve/server.rs:365-369`\n  (clones the field into resolved server settings).\n- Startup resolution: `lib/crates/fabro-server/src/server.rs:2422-2430` —\n  `slack_settings.default_channel.as_ref().map(|value|\n  value.resolve(process_env_var)...)` feeding\n  `SlackService::new(bot, app, default_channel: Option<String>)`\n  (`server.rs:589-600`). The service posts interview prompts to it\n  (`server.rs:~657` `let Some(default_channel) = ... else return`, `:689`\n  `post_message`).\n- Demoted-field warning helper: `warn_if_demoted_template` in\n  `lib/crates/fabro-config/src/resolve/` (see its callers in\n  `resolve/cli.rs:50-76` for the exact usage pattern: field path string +\n  `Option<&str>` value).\n- Run-scope channels (untouched by this PR):\n  `run.notifications.<route>` slack channel and\n  `run.interviews.slack.channel`, both `InterpString`, variable-substituted at\n  run creation (`fabro-types/src/settings/run.rs`, `substitute_variables`).\n- Docs mentioning the field (all literal examples):\n  `docs/public/administration/server-configuration.mdx:453`,\n  `docs/public/human-tools/interviews.mdx:97`,\n  `docs/public/integrations/slack.mdx:112-117`.\n- OpenAPI: `docs/public/api-reference/fabro-api.yaml:13619-13623` models\n  `default_channel` as a nullable plain string in the relevant schema —\n  expected to need **no change**.\n\n## Implementation\n\n1. **Type change**: `fabro-types/src/settings/server.rs` and\n   `fabro-config/src/layers/server.rs` — `Option<InterpString>` →\n   `Option<String>`. Chase the compiler through the resolve copy-through and\n   any settings merge/serde helpers.\n2. **Demotion warning**: at the server-settings resolve site, call the\n   existing demoted-field warning helper with the field path\n   `server.integrations.slack.default_channel` and the literal value,\n   following the exact pattern of its existing callers. The warning must log\n   the field path and guidance only — never treat the value as sensitive\n   output beyond what the existing helper does.\n3. **Drop the startup resolve**: `fabro-server/src/server.rs` — pass the\n   literal through to `SlackService::new` directly; delete the\n   `resolve(process_env_var)` call and its error mapping. `SlackService`\n   itself is unchanged (it already takes `Option<String>`).\n4. **Verify (read-only) the interview routing preference**: confirm whether\n   the interview-prompt posting path prefers `run.interviews.slack.channel`\n   over the server default when both are set. If it does not, **do not build\n   routing changes** — record the finding in the PR description as a\n   follow-up observation.\n5. **Docs**: the three pages above already show literals; adjust wording only\n   if any implies interpolation (none is expected to). If the generated\n   options reference annotates the field's type, regenerate via\n   `cargo dev docs` and confirm `cargo dev docs check` is green.\n\n## Scope boundaries — deliberately NOT in this PR\n\n- **Run-scope notification and interview channel fields** — leave as-is; they\n  are the intended interpolating surface and are already correct.\n- **Slack credential resolution** (bot/app tokens via the vault at startup) —\n  leave as-is; unrelated to the channel field.\n- **Interview prompt routing behavior** — observe and report only (step 4);\n  changing which channel wins is separate product work.\n- **Any chat-integration plugin restructuring** — future work; this PR only\n  simplifies what that redesign will inherit.\n- **The config-field kind registry and its conformance tests** — separate\n  planned work; do not start it here.\n\nIf work outside these boundaries seems genuinely required for this PR to\ncompile or pass its tests, stop and state that in the PR description rather\nthan expanding scope.\n\n## Tests (failing-first; hermetic — no ambient env dependence)\n\n- A literal channel (`#releases`) parses, merges, and reaches\n  `SlackService::new` unchanged.\n- A value containing a token-shaped span parses as a **literal** (no\n  resolution, no error) and emits the demoted-field warning naming\n  `server.integrations.slack.default_channel` (log-capture, matching how the\n  existing demotion-warning tests assert).\n- Startup wiring: with the field set, the service receives exactly the\n  configured string; with it absent, `None` (existing behavior preserved).\n- Existing Slack/server integration tests pass unchanged.\n- Serde shape: a settings round-trip of the field produces the same JSON/TOML\n  as before the type change (wire-invisibility).\n\n## Acceptance / verification\n\n- `cargo +nightly-2026-04-14 fmt --check --all`\n- `cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings`\n- `cargo nextest run --workspace`\n- `cargo dev docs check`\n- No OpenAPI/wire change (assert: `docs/public/api-reference/fabro-api.yaml`\n  untouched; TypeScript client regeneration not needed).\n\n## Conventions\n\n- Plain-English commit messages, PR text, and comments — describe what the\n  change does; no internal planning identifiers or plan-file names in\n  anything that ships.\n- PR description must state plainly: the field only ever resolved env vars,\n  only at server startup, and was never documented as interpolable; anyone\n  with a token in the field gets a startup warning and the value is treated\n  as a literal; per-run channels (`run.notifications`, `run.interviews.slack`)\n  remain the interpolating surface; no wire change.\n",
+          "failure_signature": "simplify_gpt|deterministic|api_deterministic|openai|authentication",
+          "internal.fidelity": "compact",
+          "graph.rankdir": "LR",
+          "internal.thread_id": "simplify_fable",
+          "internal.retry_count.start": 0,
+          "internal.work_dir": "/home/daytona/workspace/fabro",
+          "current_node": "simplify_gpt",
           "internal.run_id": "01KX4JRJ2NXPQASFNE8PPKTQX6",
+          "thread.toolchain.current_node": "preflight_compile",
           "failure_class": "deterministic",
+          "thread.simplify_fable.current_node": "simplify_gpt",
+          "outcome": "failed",
+          "response.simplify_fable": "## Summary\n\nThe prior \"implement\" stage had failed on an API authentication error with **zero changes committed**, so I implemented the plan from scratch, then ran the three-agent simplify review and applied its findings.\n\n### Implementation\n- **Type demotion**: `default_channel: Option<InterpString>` → `Option<String>` in `fabro-types/src/settings/server.rs:261` and `fabro-config/src/layers/server.rs:237` (unused `InterpString` import removed from fabro-types).\n- **Demotion warning**: `resolve_integrations` in `fabro-config/src/resolve/server.rs` now calls `warn_if_demoted_template(\"server.integrations.slack.default_channel\", ...)`, mirroring the adjacent GitHub arm.\n- **Dropped startup resolution**: `fabro-server/src/server.rs:2425` passes the literal straight to `SlackService::new`; the `resolve(process_env_var)` call and its error mapping are gone. Deleted the now-single-caller `display_interp` helper in `server/handler/system.rs` — the `/system/integrations` endpoint no longer does per-request template resolution.\n- **Tests**: literal pass-through + JSON wire-shape lock, token-stays-literal (mirroring `resolve_storage_root_keeps_template_token_literal`), and startup wiring tests (set → verbatim `#releases`; absent → `None`).\n\n### Step-4 finding (read-only, for the PR description)\nThe interview-prompt posting path (`SlackService::handle_event`, server.rs:657) posts **only** to the server `default_channel` and never consults `run.interviews.slack.channel` — that run-scope field is parsed and resolved but has no consumer in the posting path. Follow-up product work, not changed here. Also worth noting in the PR: previously an unresolvable env token **failed startup**; now it flows through verbatim with a resolve-time warning — the intended \"warn, don't break\" behavior.\n\n### Simplify review results\n- **Fixed**: extracted `slack_test_vault_tokens()` to replace three verbatim copies of the vault-token fixture; aligned `system.rs` to the sibling `as_ref()` + clone-at-insert pattern.\n- **Skipped (with reason)**: dropping the JSON wire-shape assert (plan explicitly requires the serde wire-invisibility test) and folding the two wiring tests into one (plan requires both the set and absent cases).\n- Reviewers confirmed clean: no dead code, correct helper reuse, field-path string style matches siblings, private-field asserts match module test style, and the diff is a net perf win (startup and per-request resolution both removed).\n\n### Verification\n- `cargo +nightly-2026-04-14 fmt --check --all` — clean\n- `cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings` — clean\n- `cargo nextest run --workspace` — 6961 passed (before final test-file cleanup; fabro-server/fabro-config re-run after: 984 passed)\n- `cargo dev docs check` — up to date; the three doc pages already show literals only\n- `docs/public/api-reference/fabro-api.yaml` — untouched; no wire change, no TS client regen needed",
+          "thread.implement.current_node": "simplify_fable",
+          "thread.preflight_lint.current_node": "implement",
+          "thread.start.current_node": "toolchain",
+          "internal.retry_count.toolchain": 0,
+          "command.output": "blob://sha256/12ae32cb1ec02d01eda3581b127c1fee3b0dc53572ed6baf239721a03d82e126",
+          "internal.node_visit_count": 1,
+          "internal.retry_count.simplify_gpt": 0,
+          "last_response": "## Summary\n\nThe prior \"implement\" stage had failed on an API authentication error with **zero changes committed**, so I implemented the plan from scratch, then ran the three-agent simplify review and "
+        },
+        "node_outcomes": {
+          "implement": {
+            "status": "failed",
+            "failure": {
+              "message": "LLM error: Authentication error for openai: Your authentication token has been invalidated. Please try signing in again.",
+              "category": "deterministic",
+              "signature": "api_deterministic|openai|authentication"
+            },
+            "usage": null
+          },
+          "simplify_fable": {
+            "status": "succeeded",
+            "context_updates": {
+              "response.simplify_fable": "## Summary\n\nThe prior \"implement\" stage had failed on an API authentication error with **zero changes committed**, so I implemented the plan from scratch, then ran the three-agent simplify review and applied its findings.\n\n### Implementation\n- **Type demotion**: `default_channel: Option<InterpString>` → `Option<String>` in `fabro-types/src/settings/server.rs:261` and `fabro-config/src/layers/server.rs:237` (unused `InterpString` import removed from fabro-types).\n- **Demotion warning**: `resolve_integrations` in `fabro-config/src/resolve/server.rs` now calls `warn_if_demoted_template(\"server.integrations.slack.default_channel\", ...)`, mirroring the adjacent GitHub arm.\n- **Dropped startup resolution**: `fabro-server/src/server.rs:2425` passes the literal straight to `SlackService::new`; the `resolve(process_env_var)` call and its error mapping are gone. Deleted the now-single-caller `display_interp` helper in `server/handler/system.rs` — the `/system/integrations` endpoint no longer does per-request template resolution.\n- **Tests**: literal pass-through + JSON wire-shape lock, token-stays-literal (mirroring `resolve_storage_root_keeps_template_token_literal`), and startup wiring tests (set → verbatim `#releases`; absent → `None`).\n\n### Step-4 finding (read-only, for the PR description)\nThe interview-prompt posting path (`SlackService::handle_event`, server.rs:657) posts **only** to the server `default_channel` and never consults `run.interviews.slack.channel` — that run-scope field is parsed and resolved but has no consumer in the posting path. Follow-up product work, not changed here. Also worth noting in the PR: previously an unresolvable env token **failed startup**; now it flows through verbatim with a resolve-time warning — the intended \"warn, don't break\" behavior.\n\n### Simplify review results\n- **Fixed**: extracted `slack_test_vault_tokens()` to replace three verbatim copies of the vault-token fixture; aligned `system.rs` to the sibling `as_ref()` + clone-at-insert pattern.\n- **Skipped (with reason)**: dropping the JSON wire-shape assert (plan explicitly requires the serde wire-invisibility test) and folding the two wiring tests into one (plan requires both the set and absent cases).\n- Reviewers confirmed clean: no dead code, correct helper reuse, field-path string style matches siblings, private-field asserts match module test style, and the diff is a net perf win (startup and per-request resolution both removed).\n\n### Verification\n- `cargo +nightly-2026-04-14 fmt --check --all` — clean\n- `cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings` — clean\n- `cargo nextest run --workspace` — 6961 passed (before final test-file cleanup; fabro-server/fabro-config re-run after: 984 passed)\n- `cargo dev docs check` — up to date; the three doc pages already show literals only\n- `docs/public/api-reference/fabro-api.yaml` — untouched; no wire change, no TS client regen needed",
+              "last_response": "## Summary\n\nThe prior \"implement\" stage had failed on an API authentication error with **zero changes committed**, so I implemented the plan from scratch, then ran the three-agent simplify review and ",
+              "last_stage": "simplify_fable"
+            },
+            "notes": "Stage completed: simplify_fable",
+            "usage": {
+              "input": {
+                "usage": {
+                  "model": {
+                    "provider": "anthropic",
+                    "model_id": "claude-fable-5"
+                  },
+                  "tokens": {
+                    "input_tokens": 86411,
+                    "output_tokens": 31302,
+                    "reasoning_tokens": 0,
+                    "cache_read_tokens": 3391207,
+                    "cache_write_tokens": 342310
+                  }
+                },
+                "facts": {
+                  "algorithm": "anthropic",
+                  "cache_write_5m_tokens": 342310,
+                  "cache_write_1h_tokens": 0
+                }
+              },
+              "total_usd_micros": 10099292
+            },
+            "files_touched": [
+              "/home/daytona/workspace/fabro/lib/crates/fabro-config/src/layers/server.rs",
+              "/home/daytona/workspace/fabro/lib/crates/fabro-config/src/resolve/server.rs",
+              "/home/daytona/workspace/fabro/lib/crates/fabro-config/src/tests/resolve_server.rs",
+              "/home/daytona/workspace/fabro/lib/crates/fabro-server/src/server.rs",
+              "/home/daytona/workspace/fabro/lib/crates/fabro-server/src/server/handler/system.rs",
+              "/home/daytona/workspace/fabro/lib/crates/fabro-server/src/server/tests.rs",
+              "/home/daytona/workspace/fabro/lib/crates/fabro-types/src/settings/server.rs"
+            ],
+            "timing": {
+              "wall_time_ms": 0,
+              "inference_time_ms": 621318,
+              "tool_time_ms": 1041791,
+              "active_time_ms": 1663109
+            }
+          },
+          "preflight_lint": {
+            "status": "succeeded",
+            "context_updates": {
+              "command.output": "blob://sha256/12ae32cb1ec02d01eda3581b127c1fee3b0dc53572ed6baf239721a03d82e126"
+            },
+            "notes": "Script completed: cargo +nightly-2026-04-14 clippy -q --workspace --all-targets -- -D warnings 2>&1",
+            "usage": null,
+            "timing": {
+              "wall_time_ms": 0,
+              "inference_time_ms": 0,
+              "tool_time_ms": 162141,
+              "active_time_ms": 162141
+            }
+          },
+          "simplify_gpt": {
+            "status": "failed",
+            "failure": {
+              "message": "LLM error: Authentication error for openai: Your authentication token has been invalidated. Please try signing in again.",
+              "category": "deterministic",
+              "signature": "api_deterministic|openai|authentication"
+            },
+            "usage": null
+          },
+          "preflight_compile": {
+            "status": "succeeded",
+            "context_updates": {
+              "command.output": "blob://sha256/12ae32cb1ec02d01eda3581b127c1fee3b0dc53572ed6baf239721a03d82e126"
+            },
+            "notes": "Script completed: cargo check -q --workspace 2>&1",
+            "usage": null,
+            "timing": {
+              "wall_time_ms": 0,
+              "inference_time_ms": 0,
+              "tool_time_ms": 161483,
+              "active_time_ms": 161483
+            }
+          },
+          "start": {
+            "status": "succeeded",
+            "usage": null
+          },
+          "toolchain": {
+            "status": "succeeded",
+            "context_updates": {
+              "command.output": "blob://sha256/20eeffec02497fbda7b51f51b06fe29c1d639551eee4d5ea9845fc1f86bd77e1"
+            },
+            "notes": "Script completed: command -v cargo >/dev/null || { curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && sudo ln -sf $HOME/.cargo/bin/* /usr/local/bin/; }; cargo --version 2>&1",
+            "usage": null,
+            "timing": {
+              "wall_time_ms": 0,
+              "inference_time_ms": 0,
+              "tool_time_ms": 1284,
+              "active_time_ms": 1284
+            }
+          }
+        },
+        "next_node_id": "verify",
+        "git_commit_sha": "56f518e0adabf8cccdfcbf1e734dfca87922050c",
+        "loop_failure_signatures": {
+          "implement|deterministic|api_deterministic|openai|authentication": 1,
+          "simplify_gpt|deterministic|api_deterministic|openai|authentication": 1
+        },
+        "node_visits": {
+          "simplify_gpt": 1,
+          "preflight_lint": 1,
+          "implement": 1,
+          "start": 1,
+          "toolchain": 1,
+          "preflight_compile": 1,
+          "simplify_fable": 1
+        }
+      },
+      "diff": {
+        "summary": {
+          "files_changed": 7,
+          "additions": 105,
+          "deletions": 35
+        }
+      }
+    },
+    {
+      "seq": 0,
+      "checkpoint": {
+        "timestamp": "2026-07-09T23:59:21.783930044Z",
+        "current_node": "verify",
+        "completed_nodes": [
+          "start",
+          "toolchain",
+          "preflight_compile",
+          "preflight_lint",
+          "implement",
+          "simplify_fable",
+          "simplify_gpt",
+          "verify"
+        ],
+        "node_retries": {},
+        "context_values": {
+          "internal.run_id": "01KX4JRJ2NXPQASFNE8PPKTQX6",
+          "failure_class": "",
           "internal.retry_count.start": 0,
           "thread.implement.current_node": "simplify_fable",
           "internal.retry_count.simplify_gpt": 0,
-          "failure_signature": "simplify_gpt|deterministic|api_deterministic|openai|authentication",
+          "failure_signature": "",
           "graph.model_stylesheet": "\n            * { model: claude-opus-4-8; }\n        ",
           "graph.goal": "# Demote `server.integrations.slack.default_channel` to a plain literal string\n\n**Self-contained implementation plan.** Everything needed to implement this is\nin this file plus the repository. Independent — no preconditions; can land\nanytime. (It must land before a separate, later effort freezes a registry of\nconfig-field kinds, but nothing in this plan depends on that.)\n\n> **Token notation.** Interpolation tokens are written in this file without\n> their enclosing double curly braces, so the file is safe to pass directly as\n> a workflow goal (the goal templater would otherwise try to expand them).\n> Read `env.NAME`, `vars.NAME`, `secrets.NAME` as the double-curly-brace token\n> form used in the codebase, and write the real double-brace syntax in the\n> code, tests, and docs you produce.\n\n## Context and goal\n\n`server.integrations.slack.default_channel` is the last server-defined config\nfield still typed `InterpString`. Every other server-scope field was demoted\nto a plain literal under the project's rule that interpolation belongs to\nfields resolved with run context — server-startup consumption is served\nnatively by shells/compose/systemd, and a token there just ferries an env var\nacross a process boundary.\n\nThis field is exactly that case:\n\n- It was **born `Option<String>`** (2026-03-05, in the original Slack\n  integration crate; adopted into server settings 2026-04-07) and was\n  documented from the start with literal examples only. The v2 settings\n  schema typed it `InterpString` (2026-04-09) and wired env resolution the\n  same day as part of that schema's uniform staged design — not a\n  field-specific feature, and never requested or documented as interpolable.\n  The one place env-interpolated Slack channels ARE a deliberate, documented\n  feature is run-scope notification routes (added 2026-05-23) — a surface\n  this change does not touch. The uniform-staging capability was superseded\n  by the later interpolation-taxonomy decision that startup-consumed server\n  fields stay literal, under which every comparable server field was already\n  demoted.\n- It resolves **once, at server startup, env-only** — no secrets, no vars,\n  and never re-resolved at message-send time.\n- **No documentation ever advertised interpolation** on it; every doc example\n  is a plain literal channel name.\n- The **run-scope interpolating surface already exists** and is the\n  user-facing one: `run.notifications.<route>.slack.channel` and\n  `run.interviews.slack.channel` are `InterpString` with variable\n  substitution at run creation. The server field is only the zero-config\n  fallback destination for interview prompts.\n- Product direction reinforces it: in hosted deployments users have no access\n  to server env at all (their surface is variables and secrets at run scope),\n  and a future chat-integration plugin system should inherit a simple literal\n  field, not a special-case interpolating one.\n\n**Goal:** change the field to a plain `Option<String>` end-to-end, drop the\nstartup resolution, and emit the standard demoted-field warning when a\nleftover token-shaped value is found — matching how the earlier server-field\ndemotions were shipped.\n\nDesign rules (fixed):\n\n- **Keep the field** as the operator's literal fallback. Do not remove it or\n  relocate it; run scope already covers per-run needs.\n- **Wire-invisible.** `InterpString` serializes as its raw source string, so\n  the stored/wire JSON shape is unchanged by this demote. The OpenAPI schema\n  already models the field as a plain string — no spec change.\n- **Warn, don't break.** A value still containing a token-shaped span (double\n  curly braces) parses fine as a literal; emit the existing demoted-field\n  warning at resolve time so the ~3 months of nightly builds where an env\n  token would have resolved get a loud, non-fatal migration signal.\n\n## Verified current state (as of main `d5dcd1179`, 2026-07-09 — re-verify before starting; line numbers are anchors, not gospel)\n\n- Type: `lib/crates/fabro-types/src/settings/server.rs:258-271` —\n  `SlackIntegrationSettings { enabled: bool, default_channel:\n  Option<InterpString> }`.\n- Config layer: `lib/crates/fabro-config/src/layers/server.rs:237` —\n  `default_channel: Option<InterpString>`.\n- Resolve copy-through: `lib/crates/fabro-config/src/resolve/server.rs:365-369`\n  (clones the field into resolved server settings).\n- Startup resolution: `lib/crates/fabro-server/src/server.rs:2422-2430` —\n  `slack_settings.default_channel.as_ref().map(|value|\n  value.resolve(process_env_var)...)` feeding\n  `SlackService::new(bot, app, default_channel: Option<String>)`\n  (`server.rs:589-600`). The service posts interview prompts to it\n  (`server.rs:~657` `let Some(default_channel) = ... else return`, `:689`\n  `post_message`).\n- Demoted-field warning helper: `warn_if_demoted_template` in\n  `lib/crates/fabro-config/src/resolve/` (see its callers in\n  `resolve/cli.rs:50-76` for the exact usage pattern: field path string +\n  `Option<&str>` value).\n- Run-scope channels (untouched by this PR):\n  `run.notifications.<route>` slack channel and\n  `run.interviews.slack.channel`, both `InterpString`, variable-substituted at\n  run creation (`fabro-types/src/settings/run.rs`, `substitute_variables`).\n- Docs mentioning the field (all literal examples):\n  `docs/public/administration/server-configuration.mdx:453`,\n  `docs/public/human-tools/interviews.mdx:97`,\n  `docs/public/integrations/slack.mdx:112-117`.\n- OpenAPI: `docs/public/api-reference/fabro-api.yaml:13619-13623` models\n  `default_channel` as a nullable plain string in the relevant schema —\n  expected to need **no change**.\n\n## Implementation\n\n1. **Type change**: `fabro-types/src/settings/server.rs` and\n   `fabro-config/src/layers/server.rs` — `Option<InterpString>` →\n   `Option<String>`. Chase the compiler through the resolve copy-through and\n   any settings merge/serde helpers.\n2. **Demotion warning**: at the server-settings resolve site, call the\n   existing demoted-field warning helper with the field path\n   `server.integrations.slack.default_channel` and the literal value,\n   following the exact pattern of its existing callers. The warning must log\n   the field path and guidance only — never treat the value as sensitive\n   output beyond what the existing helper does.\n3. **Drop the startup resolve**: `fabro-server/src/server.rs` — pass the\n   literal through to `SlackService::new` directly; delete the\n   `resolve(process_env_var)` call and its error mapping. `SlackService`\n   itself is unchanged (it already takes `Option<String>`).\n4. **Verify (read-only) the interview routing preference**: confirm whether\n   the interview-prompt posting path prefers `run.interviews.slack.channel`\n   over the server default when both are set. If it does not, **do not build\n   routing changes** — record the finding in the PR description as a\n   follow-up observation.\n5. **Docs**: the three pages above already show literals; adjust wording only\n   if any implies interpolation (none is expected to). If the generated\n   options reference annotates the field's type, regenerate via\n   `cargo dev docs` and confirm `cargo dev docs check` is green.\n\n## Scope boundaries — deliberately NOT in this PR\n\n- **Run-scope notification and interview channel fields** — leave as-is; they\n  are the intended interpolating surface and are already correct.\n- **Slack credential resolution** (bot/app tokens via the vault at startup) —\n  leave as-is; unrelated to the channel field.\n- **Interview prompt routing behavior** — observe and report only (step 4);\n  changing which channel wins is separate product work.\n- **Any chat-integration plugin restructuring** — future work; this PR only\n  simplifies what that redesign will inherit.\n- **The config-field kind registry and its conformance tests** — separate\n  planned work; do not start it here.\n\nIf work outside these boundaries seems genuinely required for this PR to\ncompile or pass its tests, stop and state that in the PR description rather\nthan expanding scope.\n\n## Tests (failing-first; hermetic — no ambient env dependence)\n\n- A literal channel (`#releases`) parses, merges, and reaches\n  `SlackService::new` unchanged.\n- A value containing a token-shaped span parses as a **literal** (no\n  resolution, no error) and emits the demoted-field warning naming\n  `server.integrations.slack.default_channel` (log-capture, matching how the\n  existing demotion-warning tests assert).\n- Startup wiring: with the field set, the service receives exactly the\n  configured string; with it absent, `None` (existing behavior preserved).\n- Existing Slack/server integration tests pass unchanged.\n- Serde shape: a settings round-trip of the field produces the same JSON/TOML\n  as before the type change (wire-invisibility).\n\n## Acceptance / verification\n\n- `cargo +nightly-2026-04-14 fmt --check --all`\n- `cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings`\n- `cargo nextest run --workspace`\n- `cargo dev docs check`\n- No OpenAPI/wire change (assert: `docs/public/api-reference/fabro-api.yaml`\n  untouched; TypeScript client regeneration not needed).\n\n## Conventions\n\n- Plain-English commit messages, PR text, and comments — describe what the\n  change does; no internal planning identifiers or plan-file names in\n  anything that ships.\n- PR description must state plainly: the field only ever resolved env vars,\n  only at server startup, and was never documented as interpolable; anyone\n  with a token in the field gets a startup warning and the value is treated\n  as a literal; per-run channels (`run.notifications`, `run.interviews.slack`)\n  remain the interpolating surface; no wire change.\n",
           "internal.fidelity": "compact",
           "thread.simplify_fable.current_node": "simplify_gpt",
           "last_response": "## Summary\n\nThe prior \"implement\" stage had failed on an API authentication error with **zero changes committed**, so I implemented the plan from scratch, then ran the three-agent simplify review and ",
           "internal.work_dir": "/home/daytona/workspace/fabro",
-          "internal.thread_id": "simplify_fable",
+          "internal.thread_id": "simplify_gpt",
           "thread.toolchain.current_node": "preflight_compile",
           "internal.retry_count.preflight_lint": 0,
           "last_stage": "simplify_fable",
@@ -1109,12 +1293,14 @@
           "internal.retry_count.preflight_compile": 0,
           "thread.preflight_lint.current_node": "implement",
           "internal.retry_count.implement": 0,
-          "current_node": "simplify_gpt",
+          "current_node": "verify",
+          "thread.simplify_gpt.current_node": "verify",
           "graph.rankdir": "LR",
           "thread.preflight_compile.current_node": "preflight_lint",
-          "command.output": "blob://sha256/12ae32cb1ec02d01eda3581b127c1fee3b0dc53572ed6baf239721a03d82e126",
+          "command.output": "blob://sha256/82be810f13e3bcdf35f62842fa33e6859d57551d10813770e8b9592418474d9d",
           "internal.node_visit_count": 1,
-          "outcome": "failed",
+          "internal.retry_count.verify": 0,
+          "outcome": "succeeded",
           "thread.start.current_node": "toolchain",
           "internal.retry_count.simplify_fable": 0,
           "internal.retry_count.toolchain": 0
@@ -1217,6 +1403,20 @@
             },
             "usage": null
           },
+          "verify": {
+            "status": "succeeded",
+            "context_updates": {
+              "command.output": "blob://sha256/82be810f13e3bcdf35f62842fa33e6859d57551d10813770e8b9592418474d9d"
+            },
+            "notes": "Script completed: git fetch origin main 2>&1 && git merge --no-edit --no-stat origin/main 2>&1 && cargo +nightly-2026-04-14 fmt --all 2>&1 && cargo dev docs refresh 2>&1 && cargo +nightly-2026-04-14 fmt --check --all 2>&1 && { command -v rg >/dev/null 2>&1 || { echo 'rg is required for verify'; exit 127; }; } && ! rg -n 'AuthMode::Disabled|RunAuthMethod|RunSubjectProvenance|\\bActorRef\\b|\\bActorKind\\b|AuthenticatedSubject|AuthenticatedService|AuthorizeRunScoped|AuthorizeRunBlob|AuthorizeStageArtifact|AuthorizeCommandLog|auth_method\\s*==\\s*\"disabled\"' lib/crates apps lib/packages docs/public/api-reference/fabro-api.yaml 2>&1 && cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings 2>&1 && cargo nextest run --workspace --status-level slow --profile ci 2>&1 && cargo dev docs check 2>&1 && bun install --frozen-lockfile 2>&1 && (cd apps/fabro-web && bun run typecheck) 2>&1 && (cd apps/fabro-web && bun run test) 2>&1 && (cd lib/packages/fabro-api-client && bun run typecheck) 2>&1 && cargo dev build -- -p fabro-cli --release 2>&1",
+            "usage": null,
+            "timing": {
+              "wall_time_ms": 0,
+              "inference_time_ms": 0,
+              "tool_time_ms": 464368,
+              "active_time_ms": 464368
+            }
+          },
           "preflight_compile": {
             "status": "succeeded",
             "context_updates": {
@@ -1232,12 +1432,13 @@
             }
           }
         },
-        "next_node_id": "verify",
+        "next_node_id": "exit",
         "node_visits": {
-          "start": 1,
           "preflight_lint": 1,
-          "simplify_gpt": 1,
+          "verify": 1,
           "toolchain": 1,
+          "start": 1,
+          "simplify_gpt": 1,
           "simplify_fable": 1,
           "implement": 1,
           "preflight_compile": 1
@@ -1612,40 +1813,6 @@
       },
       "state": "succeeded"
     },
-    "start@1": {
-      "first_event_seq": 18,
-      "prompt": null,
-      "response": null,
-      "completion": {
-        "outcome": "succeeded",
-        "notes": null,
-        "failure_reason": null,
-        "timestamp": "2026-07-09T23:18:03.802176502Z"
-      },
-      "provider_used": null,
-      "diff": null,
-      "script_invocation": null,
-      "script_timing": null,
-      "parallel_results": null,
-      "output": null,
-      "started_at": "2026-07-09T23:18:03.802023263Z",
-      "handler": "start",
-      "timing": {
-        "wall_time_ms": 0,
-        "inference_time_ms": 0,
-        "tool_time_ms": 0,
-        "active_time_ms": 0
-      },
-      "usage": {
-        "input_tokens": 0,
-        "output_tokens": 0,
-        "total_tokens": 0,
-        "reasoning_tokens": 0,
-        "cache_read_tokens": 0,
-        "cache_write_tokens": 0
-      },
-      "state": "succeeded"
-    },
     "preflight_compile@1": {
       "first_event_seq": 32,
       "prompt": null,
@@ -1746,7 +1913,12 @@
       "first_event_seq": 567,
       "prompt": null,
       "response": null,
-      "completion": null,
+      "completion": {
+        "outcome": "failed",
+        "notes": null,
+        "failure_reason": "LLM error: Authentication error for openai: Your authentication token has been invalidated. Please try signing in again.",
+        "timestamp": "2026-07-09T23:51:33.522899208Z"
+      },
       "provider_used": {
         "mode": "agent",
         "provider": "openai",
@@ -1759,6 +1931,12 @@
       "output": null,
       "started_at": "2026-07-09T23:51:33.010302877Z",
       "handler": "agent",
+      "timing": {
+        "wall_time_ms": 512,
+        "inference_time_ms": 0,
+        "tool_time_ms": 0,
+        "active_time_ms": 0
+      },
       "usage": {
         "input_tokens": 0,
         "output_tokens": 0,
@@ -1914,7 +2092,7 @@
           "invoked": false
         }
       ],
-      "state": "running"
+      "state": "failed"
     },
     "implement@1": {
       "first_event_seq": 52,
@@ -2102,6 +2280,68 @@
       ],
       "state": "failed"
     },
+    "verify@1": {
+      "first_event_seq": 584,
+      "prompt": null,
+      "response": null,
+      "completion": null,
+      "provider_used": null,
+      "diff": null,
+      "script_invocation": {
+        "script": "git fetch origin main 2>&1 && git merge --no-edit --no-stat origin/main 2>&1 && cargo +nightly-2026-04-14 fmt --all 2>&1 && cargo dev docs refresh 2>&1 && cargo +nightly-2026-04-14 fmt --check --all 2>&1 && { command -v rg >/dev/null 2>&1 || { echo 'rg is required for verify'; exit 127; }; } && ! rg -n 'AuthMode::Disabled|RunAuthMethod|RunSubjectProvenance|\\bActorRef\\b|\\bActorKind\\b|AuthenticatedSubject|AuthenticatedService|AuthorizeRunScoped|AuthorizeRunBlob|AuthorizeStageArtifact|AuthorizeCommandLog|auth_method\\s*==\\s*\"disabled\"' lib/crates apps lib/packages docs/public/api-reference/fabro-api.yaml 2>&1 && cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings 2>&1 && cargo nextest run --workspace --status-level slow --profile ci 2>&1 && cargo dev docs check 2>&1 && bun install --frozen-lockfile 2>&1 && (cd apps/fabro-web && bun run typecheck) 2>&1 && (cd apps/fabro-web && bun run test) 2>&1 && (cd lib/packages/fabro-api-client && bun run typecheck) 2>&1 && cargo dev build -- -p fabro-cli --release 2>&1",
+        "command": "exec 2>&1\ngit fetch origin main 2>&1 && git merge --no-edit --no-stat origin/main 2>&1 && cargo +nightly-2026-04-14 fmt --all 2>&1 && cargo dev docs refresh 2>&1 && cargo +nightly-2026-04-14 fmt --check --all 2>&1 && { command -v rg >/dev/null 2>&1 || { echo 'rg is required for verify'; exit 127; }; } && ! rg -n 'AuthMode::Disabled|RunAuthMethod|RunSubjectProvenance|\\bActorRef\\b|\\bActorKind\\b|AuthenticatedSubject|AuthenticatedService|AuthorizeRunScoped|AuthorizeRunBlob|AuthorizeStageArtifact|AuthorizeCommandLog|auth_method\\s*==\\s*\"disabled\"' lib/crates apps lib/packages docs/public/api-reference/fabro-api.yaml 2>&1 && cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings 2>&1 && cargo nextest run --workspace --status-level slow --profile ci 2>&1 && cargo dev docs check 2>&1 && bun install --frozen-lockfile 2>&1 && (cd apps/fabro-web && bun run typecheck) 2>&1 && (cd apps/fabro-web && bun run test) 2>&1 && (cd lib/packages/fabro-api-client && bun run typecheck) 2>&1 && cargo dev build -- -p fabro-cli --release 2>&1",
+        "language": "shell",
+        "timeout_ms": 1800000
+      },
+      "script_timing": null,
+      "parallel_results": null,
+      "output": null,
+      "started_at": "2026-07-09T23:51:37.406086657Z",
+      "handler": "command",
+      "usage": {
+        "input_tokens": 0,
+        "output_tokens": 0,
+        "total_tokens": 0,
+        "reasoning_tokens": 0,
+        "cache_read_tokens": 0,
+        "cache_write_tokens": 0
+      },
+      "state": "running"
+    },
+    "start@1": {
+      "first_event_seq": 18,
+      "prompt": null,
+      "response": null,
+      "completion": {
+        "outcome": "succeeded",
+        "notes": null,
+        "failure_reason": null,
+        "timestamp": "2026-07-09T23:18:03.802176502Z"
+      },
+      "provider_used": null,
+      "diff": null,
+      "script_invocation": null,
+      "script_timing": null,
+      "parallel_results": null,
+      "output": null,
+      "started_at": "2026-07-09T23:18:03.802023263Z",
+      "handler": "start",
+      "timing": {
+        "wall_time_ms": 0,
+        "inference_time_ms": 0,
+        "tool_time_ms": 0,
+        "active_time_ms": 0
+      },
+      "usage": {
+        "input_tokens": 0,
+        "output_tokens": 0,
+        "total_tokens": 0,
+        "reasoning_tokens": 0,
+        "cache_read_tokens": 0,
+        "cache_write_tokens": 0
+      },
+      "state": "succeeded"
+    },
     "toolchain@1": {
       "first_event_seq": 22,
       "prompt": null,
diff --git a/stages/007-simplify_gpt@1/status.json b/stages/007-simplify_gpt@1/status.json
new file mode 100644
index 000000000..ef15e1063
--- /dev/null
+++ b/stages/007-simplify_gpt@1/status.json
@@ -0,0 +1,6 @@
+{
+  "outcome": "failed",
+  "notes": null,
+  "failure_reason": "LLM error: Authentication error for openai: Your authentication token has been invalidated. Please try signing in again.",
+  "timestamp": "2026-07-09T23:51:33.522899208Z"
+}
\ No newline at end of file
diff --git a/stages/008-verify@1/script_invocation.json b/stages/008-verify@1/script_invocation.json
new file mode 100644
index 000000000..b7de73599
--- /dev/null
+++ b/stages/008-verify@1/script_invocation.json
@@ -0,0 +1,6 @@
+{
+  "script": "git fetch origin main 2>&1 && git merge --no-edit --no-stat origin/main 2>&1 && cargo +nightly-2026-04-14 fmt --all 2>&1 && cargo dev docs refresh 2>&1 && cargo +nightly-2026-04-14 fmt --check --all 2>&1 && { command -v rg >/dev/null 2>&1 || { echo 'rg is required for verify'; exit 127; }; } && ! rg -n 'AuthMode::Disabled|RunAuthMethod|RunSubjectProvenance|\\bActorRef\\b|\\bActorKind\\b|AuthenticatedSubject|AuthenticatedService|AuthorizeRunScoped|AuthorizeRunBlob|AuthorizeStageArtifact|AuthorizeCommandLog|auth_method\\s*==\\s*\"disabled\"' lib/crates apps lib/packages docs/public/api-reference/fabro-api.yaml 2>&1 && cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings 2>&1 && cargo nextest run --workspace --status-level slow --profile ci 2>&1 && cargo dev docs check 2>&1 && bun install --frozen-lockfile 2>&1 && (cd apps/fabro-web && bun run typecheck) 2>&1 && (cd apps/fabro-web && bun run test) 2>&1 && (cd lib/packages/fabro-api-client && bun run typecheck) 2>&1 && cargo dev build -- -p fabro-cli --release 2>&1",
+  "command": "exec 2>&1\ngit fetch origin main 2>&1 && git merge --no-edit --no-stat origin/main 2>&1 && cargo +nightly-2026-04-14 fmt --all 2>&1 && cargo dev docs refresh 2>&1 && cargo +nightly-2026-04-14 fmt --check --all 2>&1 && { command -v rg >/dev/null 2>&1 || { echo 'rg is required for verify'; exit 127; }; } && ! rg -n 'AuthMode::Disabled|RunAuthMethod|RunSubjectProvenance|\\bActorRef\\b|\\bActorKind\\b|AuthenticatedSubject|AuthenticatedService|AuthorizeRunScoped|AuthorizeRunBlob|AuthorizeStageArtifact|AuthorizeCommandLog|auth_method\\s*==\\s*\"disabled\"' lib/crates apps lib/packages docs/public/api-reference/fabro-api.yaml 2>&1 && cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings 2>&1 && cargo nextest run --workspace --status-level slow --profile ci 2>&1 && cargo dev docs check 2>&1 && bun install --frozen-lockfile 2>&1 && (cd apps/fabro-web && bun run typecheck) 2>&1 && (cd apps/fabro-web && bun run test) 2>&1 && (cd lib/packages/fabro-api-client && bun run typecheck) 2>&1 && cargo dev build -- -p fabro-cli --release 2>&1",
+  "language": "shell",
+  "timeout_ms": 1800000
+}
\ No newline at end of file