Starting the job-supervision slice after merging !98.

Implementation plan:

1. Add an admin job action adapter over the in-process JobManager/MaintenanceManager; no CLI/MCP subprocesses.
2. Extend job DTOs with public-safe work/coalescing identity, cancellable/retryable reasons, progress cursor/retention metadata, throughput/ETA where derivable, and explicit interrupted/cancelled/superseded states.
3. Add versioned CSRF-protected cancel/retry endpoints requiring session, same-origin, target identity, capability eligibility, and caller idempotency key. Retry will reconcile the original maintenance registration and report whether equivalent work was coalesced or a new job id was created.
4. Persist bounded idempotency receipts with the daemon-owned job snapshot so browser reload/restart cannot replay a different intent.
5. Add URL-backed job filters/detail and structured timeline; controls name the cache/repo and show the exact receipt/current state.
6. Test reconnect/reload, graceful cancel, retry coalescing, stale/duplicate idempotency, terminal/unsupported targets, expired SSE cursors, interrupted jobs, bounded retention/progress, CSRF/origin/session, and responsive browser flows.

No arbitrary priority/lock controls, raw logs, release/tag, or routine source install.

Implemented in !99: https://gitcode.com/urandon/gitcode-mcp/pull/99

Completion report:

• daemon-owned sync/RAG jobs now expose stable public work references, action eligibility, bounded progress retention, throughput/ETA where derivable, and failure-class filtering
• cancel and retry require an authenticated browser session, same-origin validation, CSRF, a retained target, supported type/state, and a bounded idempotency key
• action receipts persist only key/intent hashes, are bounded to 256 entries, replay safely after daemon restart, and distinguish cancelled/cancellation_requested plus created/coalesced/no_work_needed
• retry is a safe current maintenance reconciliation, not a promise to reproduce an obsolete historical execution
• Jobs now has URL-preserved state/type/cache/repository/failure filters, reload-safe detail, structured bounded timeline, rate-limit/retry/interruption state, explicit target confirmation, and receipt/error feedback
• browser retries reuse the same idempotency key after an interrupted response
• the real modal restores focus; Light/Dark/System remain supported with System default

Verification:

• go test ./...
• go test -race ./internal/adminhttp ./internal/servicectl
• go vet ./...
• frontend typecheck and unit tests
• Playwright Chromium: cancel, retry coalescing, interrupted response replay, filters, deep-link reload, interruption and rate-limit states; 6 passed, live-only case skipped without its environment
• deterministic embedded asset rebuild
• visual QA at the selected 1487x1058 reference viewport and 390px responsive coverage
• git diff --check

No tag, release, or go install was produced; this is one slice of the admin epic.