checkpoint

⚒️ Generated with [Fabro](https://fabro.sh)

stages/004-preflight_lint@1/output.log

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stages/004-preflight_lint@1/script_timing.json

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stages/004-preflight_lint@1/status.json

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+{
+  "outcome": "succeeded",
+  "notes": "Script completed: cargo +nightly-2026-04-14 clippy -q --workspace --all-targets -- -D warnings 2>&1",
+  "failure_reason": null,
+  "timestamp": "2026-07-09T23:23:36.687610316Z"
+}

stages/005-implement@1/prompt.md

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+Goal: # Demote `server.integrations.slack.default_channel` to a plain literal string
+
+**Self-contained implementation plan.** Everything needed to implement this is
+in this file plus the repository. Independent — no preconditions; can land
+anytime. (It must land before a separate, later effort freezes a registry of
+config-field kinds, but nothing in this plan depends on that.)
+
+> **Token notation.** Interpolation tokens are written in this file without
+> their enclosing double curly braces, so the file is safe to pass directly as
+> a workflow goal (the goal templater would otherwise try to expand them).
+> Read `env.NAME`, `vars.NAME`, `secrets.NAME` as the double-curly-brace token
+> form used in the codebase, and write the real double-brace syntax in the
+> code, tests, and docs you produce.
+
+## Context and goal
+
+`server.integrations.slack.default_channel` is the last server-defined config
+field still typed `InterpString`. Every other server-scope field was demoted
+to a plain literal under the project's rule that interpolation belongs to
+fields resolved with run context — server-startup consumption is served
+natively by shells/compose/systemd, and a token there just ferries an env var
+across a process boundary.
+
+This field is exactly that case:
+
+- It was **born `Option<String>`** (2026-03-05, in the original Slack
+  integration crate; adopted into server settings 2026-04-07) and was
+  documented from the start with literal examples only. The v2 settings
+  schema typed it `InterpString` (2026-04-09) and wired env resolution the
+  same day as part of that schema's uniform staged design — not a
+  field-specific feature, and never requested or documented as interpolable.
+  The one place env-interpolated Slack channels ARE a deliberate, documented
+  feature is run-scope notification routes (added 2026-05-23) — a surface
+  this change does not touch. The uniform-staging capability was superseded
+  by the later interpolation-taxonomy decision that startup-consumed server
+  fields stay literal, under which every comparable server field was already
+  demoted.
+- It resolves **once, at server startup, env-only** — no secrets, no vars,
+  and never re-resolved at message-send time.
+- **No documentation ever advertised interpolation** on it; every doc example
+  is a plain literal channel name.
+- The **run-scope interpolating surface already exists** and is the
+  user-facing one: `run.notifications.<route>.slack.channel` and
+  `run.interviews.slack.channel` are `InterpString` with variable
+  substitution at run creation. The server field is only the zero-config
+  fallback destination for interview prompts.
+- Product direction reinforces it: in hosted deployments users have no access
+  to server env at all (their surface is variables and secrets at run scope),
+  and a future chat-integration plugin system should inherit a simple literal
+  field, not a special-case interpolating one.
+
+**Goal:** change the field to a plain `Option<String>` end-to-end, drop the
+startup resolution, and emit the standard demoted-field warning when a
+leftover token-shaped value is found — matching how the earlier server-field
+demotions were shipped.
+
+Design rules (fixed):
+
+- **Keep the field** as the operator's literal fallback. Do not remove it or
+  relocate it; run scope already covers per-run needs.
+- **Wire-invisible.** `InterpString` serializes as its raw source string, so
+  the stored/wire JSON shape is unchanged by this demote. The OpenAPI schema
+  already models the field as a plain string — no spec change.
+- **Warn, don't break.** A value still containing a token-shaped span (double
+  curly braces) parses fine as a literal; emit the existing demoted-field
+  warning at resolve time so the ~3 months of nightly builds where an env
+  token would have resolved get a loud, non-fatal migration signal.
+
+## Verified current state (as of main `d5dcd1179`, 2026-07-09 — re-verify before starting; line numbers are anchors, not gospel)
+
+- Type: `lib/crates/fabro-types/src/settings/server.rs:258-271` —
+  `SlackIntegrationSettings { enabled: bool, default_channel:
+  Option<InterpString> }`.
+- Config layer: `lib/crates/fabro-config/src/layers/server.rs:237` —
+  `default_channel: Option<InterpString>`.
+- Resolve copy-through: `lib/crates/fabro-config/src/resolve/server.rs:365-369`
+  (clones the field into resolved server settings).
+- Startup resolution: `lib/crates/fabro-server/src/server.rs:2422-2430` —
+  `slack_settings.default_channel.as_ref().map(|value|
+  value.resolve(process_env_var)...)` feeding
+  `SlackService::new(bot, app, default_channel: Option<String>)`
+  (`server.rs:589-600`). The service posts interview prompts to it
+  (`server.rs:~657` `let Some(default_channel) = ... else return`, `:689`
+  `post_message`).
+- Demoted-field warning helper: `warn_if_demoted_template` in
+  `lib/crates/fabro-config/src/resolve/` (see its callers in
+  `resolve/cli.rs:50-76` for the exact usage pattern: field path string +
+  `Option<&str>` value).
+- Run-scope channels (untouched by this PR):
+  `run.notifications.<route>` slack channel and
+  `run.interviews.slack.channel`, both `InterpString`, variable-substituted at
+  run creation (`fabro-types/src/settings/run.rs`, `substitute_variables`).
+- Docs mentioning the field (all literal examples):
+  `docs/public/administration/server-configuration.mdx:453`,
+  `docs/public/human-tools/interviews.mdx:97`,
+  `docs/public/integrations/slack.mdx:112-117`.
+- OpenAPI: `docs/public/api-reference/fabro-api.yaml:13619-13623` models
+  `default_channel` as a nullable plain string in the relevant schema —
+  expected to need **no change**.
+
+## Implementation
+
+1. **Type change**: `fabro-types/src/settings/server.rs` and
+   `fabro-config/src/layers/server.rs` — `Option<InterpString>` →
+   `Option<String>`. Chase the compiler through the resolve copy-through and
+   any settings merge/serde helpers.
+2. **Demotion warning**: at the server-settings resolve site, call the
+   existing demoted-field warning helper with the field path
+   `server.integrations.slack.default_channel` and the literal value,
+   following the exact pattern of its existing callers. The warning must log
+   the field path and guidance only — never treat the value as sensitive
+   output beyond what the existing helper does.
+3. **Drop the startup resolve**: `fabro-server/src/server.rs` — pass the
+   literal through to `SlackService::new` directly; delete the
+   `resolve(process_env_var)` call and its error mapping. `SlackService`
+   itself is unchanged (it already takes `Option<String>`).
+4. **Verify (read-only) the interview routing preference**: confirm whether
+   the interview-prompt posting path prefers `run.interviews.slack.channel`
+   over the server default when both are set. If it does not, **do not build
+   routing changes** — record the finding in the PR description as a
+   follow-up observation.
+5. **Docs**: the three pages above already show literals; adjust wording only
+   if any implies interpolation (none is expected to). If the generated
+   options reference annotates the field's type, regenerate via
+   `cargo dev docs` and confirm `cargo dev docs check` is green.
+
+## Scope boundaries — deliberately NOT in this PR
+
+- **Run-scope notification and interview channel fields** — leave as-is; they
+  are the intended interpolating surface and are already correct.
+- **Slack credential resolution** (bot/app tokens via the vault at startup) —
+  leave as-is; unrelated to the channel field.
+- **Interview prompt routing behavior** — observe and report only (step 4);
+  changing which channel wins is separate product work.
+- **Any chat-integration plugin restructuring** — future work; this PR only
+  simplifies what that redesign will inherit.
+- **The config-field kind registry and its conformance tests** — separate
+  planned work; do not start it here.
+
+If work outside these boundaries seems genuinely required for this PR to
+compile or pass its tests, stop and state that in the PR description rather
+than expanding scope.
+
+## Tests (failing-first; hermetic — no ambient env dependence)
+
+- A literal channel (`#releases`) parses, merges, and reaches
+  `SlackService::new` unchanged.
+- A value containing a token-shaped span parses as a **literal** (no
+  resolution, no error) and emits the demoted-field warning naming
+  `server.integrations.slack.default_channel` (log-capture, matching how the
+  existing demotion-warning tests assert).
+- Startup wiring: with the field set, the service receives exactly the
+  configured string; with it absent, `None` (existing behavior preserved).
+- Existing Slack/server integration tests pass unchanged.
+- Serde shape: a settings round-trip of the field produces the same JSON/TOML
+  as before the type change (wire-invisibility).
+
+## Acceptance / verification
+
+- `cargo +nightly-2026-04-14 fmt --check --all`
+- `cargo +nightly-2026-04-14 clippy --workspace --all-targets -- -D warnings`
+- `cargo nextest run --workspace`
+- `cargo dev docs check`
+- No OpenAPI/wire change (assert: `docs/public/api-reference/fabro-api.yaml`
+  untouched; TypeScript client regeneration not needed).
+
+## Conventions
+
+- Plain-English commit messages, PR text, and comments — describe what the
+  change does; no internal planning identifiers or plan-file names in
+  anything that ships.
+- PR description must state plainly: the field only ever resolved env vars,
+  only at server startup, and was never documented as interpolable; anyone
+  with a token in the field gets a startup warning and the value is treated
+  as a literal; per-run channels (`run.notifications`, `run.interviews.slack`)
+  remain the interpolating surface; no wire change.
+
+
+## Completed stages
+- **toolchain**: succeeded
+  - Script: `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`
+  - Output:
+    ```
+    cargo 1.96.0 (30a34c682 2026-05-25)
+    ```
+- **preflight_compile**: succeeded
+  - Script: `cargo check -q --workspace 2>&1`
+  - Output: (empty)
+- **preflight_lint**: succeeded
+  - Script: `cargo +nightly-2026-04-14 clippy -q --workspace --all-targets -- -D warnings 2>&1`
+  - Output: (empty)
+
+
+Read the plan file referenced in the goal and implement every step. Make all the code changes described in the plan. Use red/green TDD. Be sure to use the rust-style-guide skill to help you follow this repo's Rust style conventions.

stages/005-implement@1/provider_used.json

@@ -0,0 +1,6 @@
+{
+  "mode": "agent",
+  "provider": "openai",
+  "model": "gpt-5.5",
+  "reasoning_effort": "xhigh"
+}