feat(planning): enforce service observability and SLOs

[seonghobae]

Summary

Implements the next bounded follow-up slice of #64 after the gateway observability foundation.

• instruments planning-service requests through the shared @life-os/observability package
• maps concrete goal and project identifiers to bounded route templates and collapses unknown paths to /unmatched
• generates or preserves UUIDv4 x-correlation-id responses without introducing tenant or identifier metric labels
• finalizes aborted requests as synthetic 499 and isolates metric initialization, completion, and reporter failures from the request pipeline
• exposes the trusted GET /v1/metrics endpoint and adds the planning-service Prometheus scrape contract
• adds target-down, multi-window availability, 500 ms latency, and 2-second tail-latency alert gates
• defines planning-service availability, latency, telemetry trust boundaries, incident response, and deployment requirements
• adds deterministic tests for route bounding, correlation replacement, aborted-request accounting, and unsupported-method failure isolation

Security and privacy boundary

Workspace, goal, project, task, cookie, authorization, request-body, query-string, and correlation values are forbidden as metric labels. Production ingress must restrict /v1/metrics to the monitoring network.

Validation gate

Merge only when formatting, lint, type checking, tests, build, AppGuardrail, SAST Semgrep, Security Scan, Commercial Readiness, CodeRabbit, and all human/security review feedback pass on the exact current head with no unresolved actionable findings.

Refs #64 and #21.

[coderabbitai]

Warning

Review limit reached

@seonghobae, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 8 minutes

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

How can I continue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

To avoid repeated limits, reduce automatic review volume by pausing incremental auto-reviews earlier, using label-based review opt-in, excluding WIP or generated PR titles, or requesting reviews manually when the PR is ready. If your team needs uninterrupted high-volume reviews, an organization admin can enable usage-based reviews.

How do review limits work?

CodeRabbit enforces per-developer PR review limits for each organization. Most developers receive the normal plan review availability.

For paid Pro and Pro+ PR reviews, CodeRabbit uses adaptive limits for sustained high-volume activity. When a developer's recent PR review activity reaches the 95th percentile or higher among CodeRabbit users, additional reviews become available more gradually as earlier reviews age out of the rolling window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 07a1ac21-5ae4-4bfb-9d09-3f7782c8a0dd

📥 Commits

Reviewing files that changed from the base of the PR and between a4d5876 and 70cf167.

📒 Files selected for processing (9)

• README.md
• apps/planning-service/package.json
• apps/planning-service/src/main.ts
• apps/planning-service/src/observability.test.ts
• apps/planning-service/src/observability.ts
• docs/operations/planning-service-level-objectives.md
• infra/observability/planning-alerts.yml
• infra/observability/prometheus.yml
• package.json

---

_{Comment @coderabbitai help to get the list of available commands.}

[seonghobae]

@coderabbitai review

[coderabbitai]

✅ Action performed

Review finished.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.