Polymorph 0.4.0a7 - audit throughput recovery

Audit throughput recovery

This corrective pre-release removes an O(history) quota query from every audit append without weakening the write boundary.

Changes

• Audit event count and logical-byte usage are maintained transactionally in SQLite.
• Quotas are still checked before inserts under BEGIN IMMEDIATE serialization.
• Inserted rows, hash-chain tail, and usage metadata receive explicit postcondition checks before commit.
• Existing audit stores receive a one-time usage backfill when opened for writing.
• Multiple writers share the same committed quota state.
• Already serialized event bytes are reused for hashing and accounting.

Measured effect on the same contended host

• Isolated 20,000-event audit median: 3,431 to 6,395 events/s, about 86% faster.
• Signed 1,000-row workflow: previous single run 143.58 rows/s; post-fix three-run median 262.95 rows/s, about 83% higher.
• Peak RSS remained near 87.3 MiB.

Battlefield 6 was using roughly 5.8 CPU cores and the GPU was device-wide near full utilization during these measurements. These values are deliberately not presented as a replacement for the controlled 375.83 rows/s idle baseline.

Verification

• Compile, Ruff, formatting, and strict mypy passed.
• Full tests passed with warnings treated as errors.
• Audit migration, rollback, multi-writer quota, runtime, and workflow regressions passed.
• scripts/validate_local.py passed, including three workflow performance gates.
• Wheel and sdist passed Twine checks.
• Clean wheel installation, audit smoke, and connector scaffold smoke passed.
• GitHub Actions remained disabled.