docs(homelab): Stage-1 facts — RLS non-super DSN, per-user token PVC, web connect URI

Per the docs-currency gate (ADR-012 shipped): record the Stage-1 deployment
facts that future sessions would otherwise rediscover the hard way.

docs/homelab-integration.md

@@ -162,3 +162,32 @@ allow per-provider when a user connects one.
 
 _Snapshot date 2026-06-02. Items marked **confirm** were not verified to a pinned source at
 snapshot time — check brain or the live cluster before depending on them._
+
+## Stage 1 — multi-user facts (verified 2026-06-03)
+
+### Postgres RLS (ADR-012)
+- **The deployed DSN MUST connect as a non-superuser, non-BYPASSRLS role.** The
+  app uses the `tapir` role (table owner, non-superuser). `FORCE ROW LEVEL
+  SECURITY` is applied on all user-owned tables; a superuser DSN silently bypasses
+  FORCE and isolation is dead in prod. Verify: `SELECT rolsuper FROM pg_roles
+  WHERE rolname = 'tapir'` must return `f`.
+- Scoping is via `set_config('tapir.current_user_id', $userID, true)` (transaction-
+  local, auto-resets on commit — never leaks across a pooled connection).
+
+### Per-user YouTube token persistence
+- Stage-1 uses the **file-backed SecretStore** at `TAPIR_SECRETS_FILE=/data/secrets.json`
+  mounted from a **PVC** (`tapir-secrets`, 64Mi, RWO). Tokens survive pod restarts.
+  Upgrading to an ESO-backed per-user SecretStore is backlog (infra#86).
+- Per-user token ref scheme: `youtube/<userID>/refresh_token` (Worker C, ADR-006).
+  The Stage-0 single ref `youtube/refresh_token` is no longer used by `serve`; it
+  remains valid for the CLI `tapir run` (single-user, host-side).
+
+### Web YouTube connect
+- Redirect URI (registered in Google OAuth client, type Web): `https://tapir.d-ma.be/oauth/youtube/callback`.
+- Config env: `TAPIR_YT_CONNECT_REDIRECT_URL=https://tapir.d-ma.be/oauth/youtube/callback`.
+  `TAPIR_YT_CLIENT_ID` / `TAPIR_YT_CLIENT_SECRET` from the Web client (not the Desktop client used for the CLI).
+
+### Identity resolution
+- `user_identities(dex_subject → user_id)` table is **intentionally NOT RLS-enabled**
+  (it's auth plumbing, holds no user data; data isolation is on the user-owned tables).
+  All data access after subject resolution goes through `withUser`.