P1-10: Decompose complex guard gates into independently testable predicates

[Dan-StrategicAutomation]

Backlog metadata

• Priority: P1
• Backlog order: P1-10
• Type: Refactor
• Area: Guard gates
• Status: Open
• Depends on: P0-08: Introduce a canonical Pydantic Scope model and shared scope loader #134, P0-09: Model persisted receipts, pending batches and skill state with Pydantic #135
• Related work: Related to P0-01: Resolve one skill per task consistently across violin_record_ptt and violin_review_batch #83, P0-05: Bootstrap the coverage-matrix and methodology-gates skeletons, and validate obligation keys at write time #123 and P0-04: Say whether a finding with evidence_complete:false is still accepted as proof, and name the remedy #124

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Summary

From the 20 September 2026 Violin dev duplication/library review, baseline 5ca0d9d6767b91fe809b2e4996c85ac65ba9e962. Priority: P1. Source locations and measurements describe the review baseline.

Scope

Refactor handlers/ptt_gates.py::_validate_phase_exit into table-driven predicates and a typed gate context; gates/hypothesis_gate.py::check_hypothesis_freshness into timestamp, receipt, target and semantic-progress checks; gates/command.py::check_command into an explicitly ordered gate pipeline.

Acceptance criteria

• Characterize current decisions, denial messages and short-circuit ordering before changing structure.
• Test each security decision independently plus representative combined failures.
• Preserve fail-closed behavior; complexity reduction alone is not acceptance.
• Keep each gate migration in a small PR; scope/target, hypothesis write and benchmark decomposition belong to their linked issues.

Dependencies / related work

Sequence after #134, #135.

#123 owns methodology skeletons and write-time obligation validation; #83 skill agreement; #124 completeness wording. These feature fixes are excluded.

Verification

Working branch: codex/review-gate-predicates, based on dev. Future PRs target dev; follow AGENTS.md and preserve fail-closed policy. Rebase dependent branches onto updated dev before implementation.

Implementation must pass uv run pytest, uv run ruff check ., uv run ruff format --check . and uv run python scripts/violin_guard.py check-release, plus the focused checks above. No implementation or test rerun is claimed by this tracking issue.