feat: authorize iOS Hermes accounts and secure session isolation

docs/ENGINEERING_LEARNINGS.md

@@ -4,6 +4,31 @@ Updated 2026-09-19 from repository source, recorded test evidence, and prior deb
 This is guidance, not a claim that hardware or server checks were rerun today.
 Read [PROJECT_STATUS.md](PROJECT_STATUS.md) for the current product scope.
 
+## Authorized accounts and transport — 2026-10-01
+
+- The latest direct request makes Hermes server-managed; do not restore model
+  selectors or `set_model` from old handoffs. Server account auth is distinct from
+  the previously canceled ChatGPT subscription/device login.
+- Scope credentials to canonical HTTPS origin, and transcripts to origin + immutable
+  user id. Never import the global legacy transcript into an authenticated account.
+- Disable bootstrap immediately on logout, invalidate/cancel pending authentication,
+  then disconnect before clearing account UI. New account identity resets drafts and
+  task stores; reject stale room transcription/control callbacks during teardown.
+- Check generation and cancellation immediately after token fetch and before
+  `room.connect`. Serialize normal mic actions with interruption actions and recheck
+  Type mode after awaits; pending Voice requests cannot enable Type-mode capture.
+- Private IP does not justify plaintext signaling. Use same-origin URLComponents WSS
+  (IPv6 safe). Exact HTTP certificate pinning does not establish the SDK's separate
+  WSS trust. Installed trusted CA and real hardware qualification may be required;
+  never introduce trust-all or plaintext fallback to bypass it.
+- A transient `/me` outage is not revocation: retain its Keychain bearer but show
+  no unverified account UI. Only 401/403 clears saved authentication. Authentication
+  URLSession is ephemeral with cookies/cache/credential persistence disabled and
+  redirects rejected to protect password/bearer origin confinement.
+- Never log data-channel payloads or bootstrap response bodies. Keep release SDK
+  logging at error. Offline auth fixtures use memory tokens, isolated preferences
+  and deterministic no-network bootstrap errors.
+
 ## Preserve behavior across UI changes
 
 - Observe nested observable objects directly where their data is rendered. Watching