Short Closure Phase Plan (Final Hardening)

Last Updated: 2026-02-28
Duration Target: 1 short phase Goal: Close remaining anti-drift and future-proofing gaps so stabilization can be formally marked CLOSED.

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Scope

This phase is intentionally limited to the 5 remaining closure items:

1. Legacy path consolidation
2. Observability completeness
3. Env/config single-source convergence
4. Release-gate test strategy hardening
5. Prompt/runtime contract hardening

No new product features in this phase.

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Workstream 1: Legacy path consolidation

Objective: Eliminate or strictly constrain non-canonical runtime/tool paths.

Deliverables:

• Legacy tool gateway is either:
  • retired, or
  • reduced to a thin adapter that always delegates to canonical executor path.
• Explicit boundary doc updated with what remains and why.
• Drift test proving parity where compatibility path still exists.

Exit criteria:

• No behavior divergence between canonical path and allowed compatibility path.
• Deprecation status is clear and test-backed.

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Workstream 2: Observability completeness

Objective: Make operational risk visible with explicit counters/signals.

Deliverables:

• Metrics/log fields for:
  • queue health/backlog/failure
  • tool denials by reason
  • per-stage turn latency
  • embedding calls per turn
• One concise runbook section mapping alert symptoms to likely root causes.

Exit criteria:

• On-call can diagnose top failure classes without code spelunking.

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Workstream 3: Env/config convergence

Objective: Ensure one validated config contract across runtime.

Deliverables:

• Verify env usage aligns with validation schema and examples.
• Remove scattered direct env-loading side paths where still present.
• Add a lightweight drift check script/test (validation vs example vs usage).

Exit criteria:

• Config onboarding and runtime behavior are deterministic across environments.

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Workstream 4: Release-gate test strategy hardening

Objective: Standardize release confidence around maintained critical-path suites.

Deliverables:

• Documented required gate commands for high-risk PRs.
• Clear policy that known-unmaintained suites are non-blocking until repaired.
• Stable curated gate remains green and repeatable.

Exit criteria:

• Release decisions no longer depend on flaky/unowned legacy suites.

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Workstream 5: Prompt/runtime contract hardening

Objective: Remove brittle parsing/string surgery from active runtime paths.

Deliverables:

• Replace fragile extraction or stripping logic in active flow with explicit structured contract.
• Add regression tests for malformed/edge formatting cases.

Exit criteria:

• Prompt/runtime behavior remains stable under template edits and unusual inputs.

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Final done definition for this closure phase

This phase is complete when all are true:

• P0 remains PASS
• P1 becomes PASS
• P2 becomes PASS or at most one clearly bounded PARTIAL with owner/date
• Required curated gate commands pass
• SYSTEM-CLOSURE-DONE-DEFINITION.md updated to Final decision: CLOSED

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Execution order

1. Legacy path consolidation
2. Env/config convergence
3. Observability completeness
4. Prompt/runtime hardening
5. Final gate run + closure record update

This order reduces drift first, then tightens operability, then seals runtime contracts.