Third reducing PR of the interpolation unification (**D11 resolution
(c)**): the control plane never interpolates. `InterpString` is now
strictly the user-facing workflow config language; server identity,
storage, listen, object-store, and GitHub App identifiers are plain
`String`, consumed where needed with no resolution point.
## Demoted to `String` (was `InterpString`)
Both the layer and resolved types:
- `server.listen.unix.path`, `server.api.url`, `server.web.url`
- `server.storage.root`, `server.artifacts.prefix`,
`server.slatedb.prefix`
- object store: `Local.root`, S3 `bucket` / `region` / `endpoint`
(shared by artifacts + slatedb)
- `github.app_id` / `client_id` / `slug`
**Kept `InterpString`:** `slack.default_channel` (run-time consumption —
the one server-defined survivor). `server.listen.tcp.address` stays the
`SocketAddr` `parsed_value` special case.
## Native `FABRO_WEB_URL` read
Deployment-time late binding now goes through a native env read instead
of a `{{ env.* }}` token: `FABRO_WEB_URL` overrides `server.web.url`
(**env override > settings literal > default**), applied in
`canonical_origin` and reused by the JWT issuer, cookie-secure check,
and system-info. `docker/split-web` no longer ferries the value through
a settings token (compose still sets the env var). `canonical_origin`'s
error message now advertises a knob that is actually true for everyone.
## Behavior change (release notes)
- `{{ env.* }}` / `{{ vars.* }}` tokens in the demoted server fields are
now **literal text**, not interpolated. The resolve layer emits
`warn_if_demoted_template` for every demoted field, so operators with
tokens still in server config **fail loud** rather than silently
treating the token as a literal.
- Operators who relied on env-based storage location should use the
existing native `FABRO_STORAGE_DIR` (`--storage-dir`) override.
`FABRO_STORAGE_ROOT` promotion is intentionally deferred (not a proven
need).
## Cleanup
`fabro-server`'s `crate::interp` shrinks to just the process-env lookup
facade; `resolve_interp` / `_path` / `_with` and the
`AppState::resolve_interp` seam are deleted (nothing resolves
server-scope `InterpString` anymore).
## Verification
- `cargo build --workspace` ✅
- `cargo +nightly clippy --workspace --all-targets -- -D warnings` ✅
(incl. the `as_source` gate)
- `cargo +nightly fmt --check --all` ✅
- `cargo nextest run --workspace`: 6305 passed; added two tests covering
the `FABRO_WEB_URL` override precedence (env-wins and settings-literal
fallback).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Permit GitHub App manifest form posts and signed HTTPS VNC preview iframes while keeping the rest of the SPA CSP locked down. Mirror the policy in the split-web Caddy config.
## Summary
Adds a standalone Docker Compose proof that runs the Fabro Rust API, a
Caddy static SPA server, and a Caddy edge proxy as separate services.
This demonstrates split web asset serving while keeping `/api/*`,
`/auth/*`, and `/health` same-origin with the API server.
## Changes
- Adds `docker-compose.split-web.yaml` with private `fabro-api` and
`fabro-web` services behind an exposed `edge` proxy on port 8080.
- Adds Caddy edge routing that sends `/api/*`, `/auth/*`, and `/health`
to Rust, while everything else goes to the static web service.
- Adds a static Caddy config for `apps/fabro-web/dist` with SPA
fallback, source-map blocking, security headers, immutable asset
caching, and `X-Fabro-PoC-Upstream` route-proof headers.
- Adds PoC server settings and a README with build, run, and validation
commands.
## Verification
- `cargo dev docker-build --tag fabro-sh/fabro:split-web-poc`
- `docker compose -f docker-compose.split-web.yaml up -d`
- `docker compose -f docker-compose.split-web.yaml ps`
- `curl` checks for `/runs`, `/assets/app.css`, `/assets/app.css.map`,
`/api/v1/health`, `/api/v1/auth/config`, `/auth/login/dev-token`,
`/api/v1/auth/me`, and `/api/v1/attach`
- Browser login flow via `browser-use`: loaded `/login`, submitted the
dev token, and landed on the authenticated Runs screen
- `docker compose -f docker-compose.split-web.yaml config`
- `caddy validate` for both Caddyfiles
- `git diff --check`
---
[](https://github.com/EveryInc/compound-engineering-plugin)
🤖 Generated with GPT-5 via [Codex](https://openai.com/codex)
