Merge pull request 'fix(gro-1866): add session-from-auth portal endpoint + role scope' (#93) from fix/gro-1866-sso-bridge into dev

fix(gro-1866): add session-from-auth portal endpoint + role scope (#93)

Bridges Better Auth SSO sessions to portal sessions for real customers.
Adds role to genericOAuth scopes for Authentik role propagation.

Closes GRO-1866

UAT_PLAYBOOK.md

@@ -163,6 +163,10 @@ GroomBook API is a Hono-based REST service (TypeScript/Node.js) powering the pet
 | TC-API-8.5 | Add waitlist entry | POST /api/portal/waitlist with pet and service | 201 Created, waitlist entry created |
 | TC-API-8.6 | View portal invoices | GET /api/portal/invoices | 200 OK, list of client's invoices returned |
 | TC-API-8.7 | Pay multiple invoices | POST /api/portal/invoices/pay-multiple with invoice IDs | 200 OK, payment intent created |
+| TC-API-8.8 | SSO bridge — valid Better Auth session | POST /api/portal/session-from-auth with valid Better Auth session cookie (authenticated SSO user with matching client email) | 201 Created, `{sessionId, clientId, clientName}` returned |
+| TC-API-8.9 | SSO bridge — no Better Auth session | POST /api/portal/session-from-auth without Better Auth session cookie | 401 Unauthorized |
+| TC-API-8.10 | SSO bridge — no matching client | POST /api/portal/session-from-auth with valid Better Auth session for a user with no client record | 404 Not Found, error "No client record found for this user" |
+| TC-API-8.11 | SSO bridge — returned session works on portal routes | After TC-API-8.8, use returned sessionId as `X-Impersonation-Session-Id` header on GET /api/portal/me | 200 OK, client profile returned |
 
 ### 4.9 Waitlist