Merge pull request 'architect: edge-subpath-chat (#623)' (#37) from architect/edge-subpath-chat into main

sprints/edge-subpath-chat.md

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+# Sprint: edge-subpath-chat
+
+## Vision issues
+- #623 — vision: subpath routing + Forgejo-OAuth-gated Claude chat inside the edge container
+
+## What this enables
+After this sprint, an operator running `disinto edge register` gets a single URL — `<project>.disinto.ai` — with Forgejo at `/forge/`, Woodpecker CI at `/ci/`, a staging preview at `/staging/`, and an OAuth-gated Claude Code chat at `/chat/`, all under one wildcard cert and one bootstrap password. The factory talks back to its operator through a chat window that sits next to the forge, CI, and live preview it is driving.
+
+## What exists today
+The majority of this vision is already implemented across issues #704–#711:
+
+- **Subpath routing**: Caddyfile generator produces `/forge/*`, `/ci/*`, `/staging/*`, `/chat/*` handlers (`lib/generators.sh:780–822`). Forgejo `ROOT_URL` and Woodpecker `WOODPECKER_HOST` are set to subpath values when `EDGE_TUNNEL_FQDN` is present (`bin/disinto:842–847`).
+- **Chat container**: Full OAuth flow via Forgejo, HttpOnly session cookies, forward_auth defense-in-depth with `FORWARD_AUTH_SECRET`, per-user rate limiting (hourly/daily/token caps), conversation history in NDJSON (`docker/chat/server.py`).
+- **Sandbox hardening**: Read-only rootfs, `cap_drop: ALL`, `no-new-privileges`, `pids_limit: 128`, `mem_limit: 512m`, no Docker socket. Verification script at `tools/edge-control/verify-chat-sandbox.sh`.
+- **Edge control plane**: Tunnel registration, port allocation, Caddy admin API routing, wildcard `*.disinto.ai` cert via DNS-01 (`tools/edge-control/`).
+- **Dependencies #620/#621/#622**: Admin password prompt, edge control plane, and reverse tunnel — all implemented and merged.
+- **Subdomain fallback plan**: Fully documented at `docs/edge-routing-fallback.md` with pivot criteria.
+
+## Complexity
+- ~6 files touched across 3 subsystems (Caddy routing, chat backend, compose generation)
+- Estimated 4 sub-issues
+- ~90% gluecode (wiring existing pieces), ~10% greenfield (WebSocket streaming, end-to-end smoke test)
+
+## Risks
+- **Forgejo/Woodpecker subpath breakage**: Neither service is battle-tested under subpaths in this stack. Redirect loops, OAuth callback mismatches, or asset 404s are plausible. Mitigation: the fallback plan (`docs/edge-routing-fallback.md`) is already documented and estimated at under one day to pivot.
+- **Cookie/CSRF collision**: Forgejo and chat share the same origin — cookie names or CSRF tokens could collide. Mitigation: chat uses a namespaced cookie (`disinto_chat_session`) and a separate OAuth app.
+- **Streaming latency**: One-shot `claude --print` blocks until completion. Long responses leave the operator staring at a spinner. Not a correctness risk, but a UX risk that WebSocket streaming would fix.
+
+## Cost — new infra to maintain
+- **No new services** — all containers already exist in the compose stack
+- **No new scheduled tasks or formulas** — chat is a passive request handler
+- **One new smoke test** (CI) — end-to-end subpath routing verification
+- **Ongoing**: monitoring Forgejo/Woodpecker upstream for subpath regressions on upgrades
+
+## Recommendation
+Worth it. The vision is ~80% implemented. The remaining work is integration hardening (confirming subpath routing works end-to-end with real Forgejo/Woodpecker) and one UX improvement (WebSocket streaming). The risk is low because a documented fallback to per-service subdomains exists. Ship this sprint to close the loop on the edge experience.
+
+## Sub-issues
+
+<!-- filer:begin -->
+- id: subpath-routing-smoke-test
+  title: "vision(#623): end-to-end subpath routing smoke test for Forgejo + Woodpecker + chat"
+  labels: [backlog]
+  depends_on: []
+  body: |
+    ## Goal
+    Verify that Forgejo, Woodpecker, and chat all function correctly when served
+    under /forge/, /ci/, and /chat/ subpaths on a single domain. Catch redirect
+    loops, OAuth callback failures, and asset 404s before they hit production.
+    ## Acceptance criteria
+    - [ ] Forgejo login at /forge/ completes without redirect loops
+    - [ ] Forgejo OAuth callback for Woodpecker succeeds under subpath
+    - [ ] Woodpecker dashboard loads all assets at /ci/ (no 404s on JS/CSS)
+    - [ ] Chat OAuth login flow works at /chat/login
+    - [ ] Forward_auth on /chat/* rejects unauthenticated requests with 401
+    - [ ] Staging content loads at /staging/
+    - [ ] Root / redirects to /forge/
+    - [ ] CI pipeline added to .woodpecker/ to run this test on edge-related changes
+
+- id: websocket-streaming-chat
+  title: "vision(#623): WebSocket streaming for chat UI to replace one-shot claude --print"
+  labels: [backlog]
+  depends_on: [subpath-routing-smoke-test]
+  body: |
+    ## Goal
+    Replace the blocking one-shot claude --print invocation in the chat backend with
+    a WebSocket connection that streams tokens to the UI as they arrive.
+    ## Acceptance criteria
+    - [ ] /chat/ws endpoint accepts WebSocket upgrade with valid session cookie
+    - [ ] /chat/ws rejects upgrade if session cookie is missing or expired
+    - [ ] Chat backend streams claude output over WebSocket as text frames
+    - [ ] UI renders tokens incrementally as they arrive
+    - [ ] Rate limiting still enforced on WebSocket messages
+    - [ ] Caddy proxies WebSocket upgrade correctly through /chat/ws with forward_auth
+
+- id: chat-working-dir-scoping
+  title: "vision(#623): scope Claude chat working directory to project staging checkout"
+  labels: [backlog]
+  depends_on: [subpath-routing-smoke-test]
+  body: |
+    ## Goal
+    Give the chat container Claude session read-write access to the project working
+    tree so the operator can inspect, explain, or modify code — scoped to that tree
+    only, with no access to factory internals, secrets, or Docker socket.
+    ## Acceptance criteria
+    - [ ] Chat container bind-mounts the project working tree as a named volume
+    - [ ] Claude invocation in server.py sets cwd to the workspace directory
+    - [ ] Claude permission mode is acceptEdits (not bypassPermissions)
+    - [ ] verify-chat-sandbox.sh updated to assert workspace mount exists
+    - [ ] Compose generator adds the workspace volume conditionally
+
+- id: subpath-fallback-automation
+  title: "vision(#623): automate subdomain fallback pivot if subpath routing fails"
+  labels: [backlog]
+  depends_on: [subpath-routing-smoke-test]
+  body: |
+    ## Goal
+    If the smoke test reveals unfixable subpath issues, automate the pivot to
+    per-service subdomains so the switch is a single config change.
+    ## Acceptance criteria
+    - [ ] generators.sh _generate_caddyfile_impl accepts EDGE_ROUTING_MODE env var
+    - [ ] In subdomain mode, Caddyfile emits four host blocks per edge-routing-fallback.md
+    - [ ] register.sh registers additional subdomain routes when EDGE_ROUTING_MODE=subdomain
+    - [ ] OAuth redirect URIs in ci-setup.sh respect routing mode
+    - [ ] .env template documents EDGE_ROUTING_MODE with a comment referencing the fallback doc
+<!-- filer:end -->