feat: BizGaze Connect home, BizGaze login, modular backend, /api/v1

User-facing
- New post-login home (/home): chat rail + Share/Connect (embedded) + Meeting; login lives here when logged out
- Landing: "Log in with BizGaze" + no-login screen share
- Console replaced by a role-scoped Dashboard (/dashboard): admins see all team sessions, others see only their own; stats + CSV/PDF export
- Recordings saved as MP4 (H.264/AAC) with WebM fallback; old .webm still downloadable
- Fix: duplicate "Sign in" on the login card

Auth / integration
- BizGaze as identity provider: /api/login validates against BIZGAZE_LOGIN_URL (env-gated) and provisions a local user
- Phase 2 start: /api/v1 alias for all /api routes; Authorization: Bearer accepted across HTTP + WS; login returns a token (for native desktop/mobile clients)

Backend refactor (Phase 1, behavior-preserving)
- Split server.js into config/lib/session/presence/routes/static/signaling + repos (data-access) + bizgaze (service)
- All SQL behind repos.js, tenant-scoped (tenantId == team_id for now)
- e2e updated to current flow (21/21 pass before and after)

Docs: ARCHITECTURE.md (target architecture + phased plan), CLAUDE.md repo layout, .env.example BIZGAZE_LOGIN_URL

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.env.example

@@ -12,6 +12,10 @@ TURN_CREDENTIAL=
 # Optional: open self-registration of the first/any team (1 to enable).
 # ALLOW_REGISTRATION=1
 
+# Optional: BizGaze as the identity provider. When set, /api/login validates
+# credentials against this endpoint (after a local check) and provisions the user.
+# BIZGAZE_LOGIN_URL=https://c02.bizgaze.app/Account/ValidateAndLogin
+
 # Optional: shared secret for BizGaze SSO + signed webhook delivery.
 # SSO_SECRET=