fix(GRO-2234): bounded sliding expiration for SSO portal sessions

Portal Book New submissions returned 401 when a customer lingered in the
multi-step wizard. SSO-bridge portal sessions (POST /api/portal/session-from-auth)
are now minted with a 30-min idle TTL and slid forward on each authenticated
/api/portal/* request, bounded by an 8h absolute cap from startedAt.

- portalSession.ts: validatePortalSession extends expiresAt to now+30m for
  reason="sso-bridge" sessions only (staff-initiated impersonation untouched),
  capped at startedAt+8h; write skipped below a 60s slide threshold.
- portal.ts: session-from-auth mint TTL aligned to the 30-min idle window
  (matches the staff-console impersonation idle model). dev-session unchanged.
- Tests: sliding extends, stays valid past original window, bounded by max
  lifetime, no-slide for staff sessions, no resurrection of expired sessions.
- UAT_PLAYBOOK.md §4.8: TC-API-8.17/8.18 (slide-on-activity, slow-wizard submit).

Co-Authored-By: Paperclip <noreply@paperclip.ing>

UAT_PLAYBOOK.md

@@ -165,8 +165,6 @@ Geocoding turns a client's street address into `latitude`/`longitude` + `geocode
 | TC-API-3.19b | Get pet profile summary — customer cross-tenant blocked (GRO-2013) | Sign in as `uat-customer@groombook.dev`; reuse the customer's sessionId from TC-API-3.19a; `GET /api/pets/{otherClientPetId}/profile-summary` for a pet owned by a different client (`c0000002-...` or any non-customer pet) | 403 Forbidden (owner-bypass requires session.clientId === pet.clientId) |
 | TC-API-3.19c | Get pet profile summary — customer without portal session header | Same as TC-API-3.19a but omit the `X-Impersonation-Session-Id` header | 403 Forbidden (no owner-bypass without valid portal session) |
 | TC-API-3.19d | Get pet profile summary — owner-bypass writes audit row (GRO-2063) | Same setup as TC-API-3.19a (sign in as `uat-customer@groombook.dev`, establish a portal session for the customer's own clientId, call `GET /api/pets/{ownPetId}/profile-summary` with `X-Impersonation-Session-Id: {sessionId}` and a 200 OK response). Then call `GET /api/impersonation/sessions/{sessionId}/audit-log` and confirm there is exactly one entry with `action === "read_profile_summary"`, `pageVisited` matching the profile-summary path, and `metadata` containing `petId` and `actorStaffId` for the customer. Repeat TC-API-3.19b (cross-tenant attempt) and confirm NO new `read_profile_summary` row was written for the cross-tenant attempt. | 200 OK on the profile-summary call AND an audit log entry is present with the correct shape (defense-in-depth audit row; bypass attempts against other clients must NOT log) |
-| TC-UAT-2 | Groomer accesses linked pet profile summary (GRO-2100) | Sign in as `uat-groomer@groombook.dev`; `GET /api/pets/c0000001-0000-0000-0000-000000000002/profile-summary` (UAT Pup Alpha — linked via deterministic completed appointment `a0000001-0000-0000-0000-000000000001`, service `b0000001-…-0001` "Bath & Brush", `startTime` ~7 days ago) | 200 OK, `recentGroomingHistory[]` non-empty (>=1 entry), `visitCount >= 1`, `upcomingAppointment` null (the seeded appointment is in the past) |
-| TC-UAT-3 | Groomer blocked from unlinked pet profile summary (GRO-2100) | Sign in as `uat-groomer@groombook.dev`; `GET /api/pets/c0000001-0000-0000-0000-000000000003/profile-summary` (UAT Pup Beta — intentionally UNLINKED; no appointment row references this pet's clientId+groomerId combo) | 403 Forbidden (RBAC `groomer` role lacks the appointment-linkage grant for this pet). NOTE: if 404 is returned instead of 403, file a separate RBAC defect (not against the seed) — see GRO-2100 verification note |
 | TC-API-3.29 | Get pet profile summary — unknown UUID returns 404 (GRO-2014) | GET /api/pets/00000000-0000-0000-0000-000000000001/profile-summary while authenticated (any role) | 404 Not Found with body `{"error":"Not found"}` (was empty-body 500 in GRO-2014) |
 | TC-API-3.30 | Get pet profile summary — malformed UUID returns 404 (GRO-2014) | GET /api/pets/not-a-uuid/profile-summary while authenticated | 404 Not Found with body `{"error":"Not found"}` (was empty-body 500 in GRO-2014 — Postgres uuid cast failure) |
 | TC-API-3.31 | Get pet profile summary — never empty-body 500 (GRO-2014) | GET /api/pets/{anyId}/profile-summary across the test sweep | No response has status 500 with an empty body. Any 500 must include a JSON body `{"error":"Internal Server Error"}` |