[Project Data] Implement transactional store and recovery

[yutthaphon]

Problem

The slice must survive save, reopen, forced closure, migration, cache deletion, and worker failure without corrupting project truth.

Change

Complete the bounded work for this issue without importing later milestone scope.

Behavior

Before: The required capability, decision, or evidence is incomplete.
After: The named outcome is reviewable and satisfies its linked specification and milestone gates.

Acceptance

• Dependencies and stable IDs are linked.
• Observable acceptance evidence is recorded.
• Security, compatibility, recovery, Windows, EN/TH, theme, and accessibility impacts are handled where applicable.
• No local Plan/ file is uploaded.

[yutthaphon]

Phase 00 Validation Acceptance — VID-IMPL-P00-005

Checkpoint: C4 (Hash-Gate Executed-Evidence Review)
Status: ACCEPTED
Acceptance Date: 2026-08-03
Test Results: Hash-Gate All Passes (7/7 captures PASS; immutability PASS; aggregate digest PASS)
Independent Review: haiku (C4 post-execution evidence verification, fresh-context independent)
Scope Boundaries: Deterministic byte-provenance gate for exact 39-file Rust baseline (1 Cargo.toml, 9 src modules, 8 test modules, 21 fixtures); immutability proof via pass A/B agreement; no runtime execution, no compilation, no tests, no waveform access.

Evidence:

• G1 Validation Readiness: .agents/handoffs/implementation-builder/VID-IMPL-P00-005-g1-validation.md (ready, not yet executed)
• C4 Hash-Gate Executed-Evidence Review: .agents/reviews/P00/haiku-vid-impl-p00-005-hash-executed-evidence-review-c4.md (verdict: ACCEPT)
• Hash-Gate Captures: .agents/validation/VID-IMPL-P00-005/hash-gate/ (7 JSON files: baseline, expected-inputs, hash-results-pass-a, hash-results-pass-b, immutability-check, hash-aggregate, hash-gate-state)
• Immutability Proof: pass_a_count=39, pass_b_count=39, passes_identical=true, files_unchanged_during_run=true, status=PASS
• Aggregate Corpus Digest: c9a54e29240990346f9566d8dddcac8018b3491cea584792917fb2bf4b9b9510 (39-line ordered preimage, UTF-8 no BOM, LF-joined)

Blocking Gates: None (G1 validation ready; hash-gate execution complete and accepted; no further pre-execution gates)

Next Phase: Ready for coordinator authorization and G1 full validation execution (compile/test/runtime gates pending)

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Sync checkpoint: github-agent C4 / haiku runtime / 2026-08-03