Closes #176. Parent #173, original feature input #101; milestone Daemon observability feature.

Scope and design

• One shared bounded summary/metrics/events reader across authenticated Admin GET, private observability.v1 IPC, CLI service observe/metrics/events, and read-only MCP tools on stdio and HTTP/SSE.
• Strict exact-key request/response contracts, closed compatible filters, opaque known-entity references, generation/filter-bound cursors, explicit byte/history/scan limits, fixed safe errors, and one cancellable two-second IPC negotiation/query budget.
• Observation/discovery bypass cache, credential and provider bootstrap. Cache-dependent MCP operations initialize lazily with serialized admission and active-store leases; explicitly requested live operations retain provider confirmation, idempotency and audit rather than fixture fallback.
• Compact body-free SSE invalidation is limited relative to actual publication; safe-copy DTOs come only from already-returned trusted evidence and are capped at16KiB.

Design/progress/corrections are in #176 comments193195756,193195952,193195998,193200736,193200859. Original issue title/body remain fixed.

Risk, recovery and UX

Shared MCP bootstrap and private IPC ownership are broad runtime changes. Tests cover damaged/old/future/parent-fault caches, missing credentials, explicit later live writes, held locks, silent/oversized/malformed peers, shutdown and source correlation. No schema migration, daemon installation/start, model/provider setup or release is performed by this PR. Recovery is fix-forward/revert of this increment without replacing durable source or execution authorities.

This is backend O3, not completed feature rollout. O4/#177 owns the explicit Admin UI cohort; O5/#178 owns integrated qualification and #187/#188 disposition. Those remain rollout dependencies of #173/#101.

Verification

Reviewed candidate20aa51ef71c2024434f9a4afb4659dc9399b3120.

• Final serial go test -p 1 ./... -count=1: PASS; an earlier overlapping-suite timing failure is preserved in issue comment193200736, with no test-limit change.
• Full affected race: observability, servicectl, adminhttp, mcp, auth, cli, cmd/gitcode-mcp PASS.
• go vet ./..., product-document contracts and immutable-range git diff --check: PASS.
• Cohort local Admin asset check, Svelte check, unit tests and semantic Playwright: PASS61/skip1 explicitly opt-in local visual test; artifact guard PASS. No frontend source changes or screenshots/video/traces in CI.
• Four original independent P2 findings and Admin path mismatch corrected; retained independent probes PASS×3 on this candidate. Independent exact-SHA code review is CLEAR/no remaining P0–P2 (latest review-clear issue comment); corrected-head CI is still blocked on mirror propagation and must be green before merge.

No merge around red/unknown checks; resulting-main CI must be observed before issue closure.