feat(v1.1.6): realtime channels + v1.1.5 follow-ups + version bumps

Server-side realtime SSE on per-app pub/sub topics, plus the three
v1.1.5 follow-ups and the version bumps.

Realtime:
- topics registry (0021) + admin endpoints + Capability::AppTopicManage
  (-> app:admin; no new scope).
- GET /realtime/topics/{topic} SSE endpoint (orchestrator-core data
  plane): Host -> app, RealtimeAuthority gate (404 missing/internal,
  401 bad/absent token), broadcast::Receiver stream + heartbeat.
- RealtimeBroadcaster / RealtimeEvent / RealtimeAuthority traits
  (picloud-shared); InProcessBroadcaster + GC (orchestrator-core);
  DB-backed RealtimeAuthorityImpl (manager-core). Publish path fans out
  to in-process subscribers after the durable outbox commit (best-effort,
  panic-isolated).
- HMAC subscriber tokens (subscriber_token.rs) + app_secrets table (0022)
  + pubsub::subscriber_token SDK (schema 1.6 -> 1.7). TTL clamp + env
  overrides.
- Dashboard Topics tab (register/list/edit/delete, prominent external
  badge, flip confirmation).

v1.1.5 follow-ups:
- Empty blobs accepted (NewFile/FileUpdate::validate) + round-trip test.
- Orphan *.tmp.* sweeper (spawn_files_orphan_sweep).
- Dispatcher e2e tests, one per trigger kind (DATABASE_URL-gated).

Versions: workspace 1.1.6, SDK 1.7, dashboard 0.12.0. Schema-snapshot
golden re-blessed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/orchestrator-core/Cargo.toml

@@ -23,8 +23,13 @@ chrono.workspace = true
 reqwest.workspace = true
 rhai.workspace = true
 tokio.workspace = true
+tokio-stream.workspace = true
 urlencoding.workspace = true
 
 # v1.1.3 — top-level script AST cache lives in orchestrator-core's
 # LocalExecutorClient; key is ScriptId, value is `(updated_at, Arc<rhai::AST>)`.
 lru.workspace = true
+
+[dev-dependencies]
+# `ServiceExt::oneshot` for driving the SSE router in unit tests.
+tower.workspace = true