feat(web): split SPA from oikos binary, require auth on every route

Phase 0 of plans/2026-07-12-wails-desktop-app.md. The control-room SPA
is no longer embedded (web/embed.go deleted); it's a standalone static
build served separately (make ui / make deploy-ui). The api process
adds CORS and drops the dev-open auth bypass — every route now needs a
real bearer token, including SSE (?token= query param, EventSource
can't set headers) and api's own /agent proxy to nomos (previously
unauthenticated by omission).

nomos was an unauthenticated client of api's /mcp and approval-decision
endpoints; closing dev-open would have broken it, so it now sends
Authorization: Bearer $OIKOS_MCP_BEARER_TOKEN on every call back to api.

SPA gets a runtime config module (config.ts) and a Config.svelte
first-launch/reconfigure page, reachable afterwards via a "Connection"
entry in the sidebar footer. Every fetch() in api.ts routes through
fetchWithAuth so the same build works same-origin (browser prod, Vite
dev proxy) or cross-origin (future Wails webview, remote access).

Six gaps found against the plan and the live Caddy topology while
implementing — documented in the plan's "Plan review" section, most
notably: api's own /agent mount was never behind combinedAuth (fixed),
and production's Authentik forward-auth needs a bearer-token bypass for
API routes that this repo's Caddyfile.oikos reference copy now has, but
the real dtoro/caddy-conf deploy does not yet.

Verified live: cross-origin static SPA + API, CORS, bearer auth, SSE
query-token auth, and localStorage persistence all confirmed working
in-browser. Full Go test suite and npm run build pass with no
regressions against the pre-change baseline.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CONTRIBUTING.md

@@ -9,10 +9,13 @@ repo, see [.agents/dev/CONTRIBUTING.md](.agents/dev/CONTRIBUTING.md).
 - **Go 1.26+** (see `go.mod` for pinned version)
 - **PostgreSQL with TimescaleDB** — the compose stack includes `timescale/timescaledb:2.17.2-pg16`
 - **Docker** for the full dev stack
+- **Node 22+** for `web/` (the control-room SPA — standalone, not part of the
+  compose stack or the `oikos` binary)
 
 ```bash
-# Start dependencies (Postgres + Redis)
-docker compose --profile dev up -d
+# Start dependencies (Postgres + Redis). api/nomos require a shared bearer
+# token — no dev-open bypass — so set one even for local dev.
+OIKOS_MCP_BEARER_TOKEN=dev-token docker compose --profile dev up -d
 
 # Run all tests
 make test
@@ -22,6 +25,9 @@ make test-db
 
 # Build the binary
 make build
+
+# SPA dev server (proxies to api/nomos, injecting the same token)
+cd web && OIKOS_API_TOKEN=dev-token npm run dev
 ```
 
 ## Project structure
@@ -42,6 +48,8 @@ internal/           All Go packages
   domain/           Core types: entities, approvals, signals, patterns
   ontology/         Type hierarchy, relationship validation
   knowledge/        Knowledge YAML seed ingestion
+web/                Control-room SPA (Svelte 5) — standalone, not embedded
+                    in the oikos binary; see plans/2026-07-12-wails-desktop-app.md
 api/openapi.yaml    API contract — the source of truth for endpoints
 migrations/         Forward-only SQL migrations (TimescaleDB)
 seeds/              Bootstrap YAML: ontology, inventory, policy, knowledge
@@ -68,6 +76,8 @@ docs/adr/           Architecture decision records
 | `make export` | Export DB state to YAML seeds |
 | `make dev` | Start compose dev stack |
 | `make clean` | Remove binary + test cache |
+| `make ui` | Build the SPA (`web/dist/`) |
+| `make deploy-ui` | Build + deploy the SPA to the Caddy host |
 
 ## Conventions