feat: add collaborative interview scheduling

Add candidate decisions, co-interviewer accounts, scheduled interview inbox and calendar views, candidate-safe meeting links, shared documents, and private live notes backed by RabbitMQ.

Extend the disposable integration environment to validate PostgreSQL migrations, seeded users, interview lifecycle behavior, and RabbitMQ fanout.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.github/copilot-instructions.md

@@ -5,9 +5,9 @@
 Run repository-wide commands from the root:
 
 ```bash
-make dev                 # run PostgreSQL, API, and frontend with development fixtures
-make test                # complete suite, including disposable PostgreSQL integration tests
-make test-integration    # Go tests; starts its own PostgreSQL Testcontainer
+make dev                 # run PostgreSQL, RabbitMQ, API, and frontend with development fixtures
+make test                # complete suite, including disposable infrastructure integration tests
+make test-integration    # Go tests; starts PostgreSQL and RabbitMQ Testcontainers
 make test-env            # isolated seeded UI stack at http://localhost:15173
 make test-env-down       # remove the test stack and its PostgreSQL volume
 make lint                # go vet and ESLint
@@ -33,6 +33,10 @@ The required toolchain is Go 1.27.1 and React 19.3 with TypeScript/Vite. Use
   `internal/database/{repository,mapper,entity}`. Never expose GORM entities from
   handlers.
 - `backend/cmd/seed` applies embedded environment-aware fixtures.
+- `backend/internal/eventbus` publishes persisted interview notes to the durable
+  `go-guess.interview-notes` RabbitMQ fanout exchange. Each API instance consumes
+  through its own exclusive queue and distributes events to authenticated SSE
+  subscribers.
 - `frontend/src/App.tsx` owns routing/layout/screens, `src/api.ts` is the typed HTTP
   boundary, and `src/types.ts` contains client domain types. Vite proxies `/api` to
   the Go service in development.
@@ -63,6 +67,14 @@ questions are acceptance-gated and answers are saved before final submission;
 interviewer review uses
 `GET /api/jobs/{id}/invitations/{invitationId}`.
 
+Only completed assessment invitations can receive a `passed` or `failed` outcome,
+and only passed candidates can be scheduled for an interview. Scheduled
+interviews include the creator plus selected co-interviewers. Attendees manage
+their invitation through `/api/inbox`, see accepted interviews in `/api/calendar`,
+and can write notes only after the interview has started. Notes are private to
+authenticated attendees. The opaque `/participant/meeting/:candidateToken` view
+exposes only candidate-safe schedule and shared-document data.
+
 ## Repository conventions
 
 - Prefix every Go interface name with `I`.