[getdownandcode]

Summary

Implements Phase 6 (Cost Control & Telemetry) for gitmate.

Deliverables

• Model Pricing Table & Cost Estimation: Model pricing registry for known models (gemini-3.5-flash-lite, gemini-3-flash, claude-3-5-sonnet, etc.) with $0.00 for cache hits and template fallbacks.
• SQLite Schema Evolution: Non-destructive ALTER TABLE migration adding estimated_cost_usd REAL to invocations table in ~/.local/share/gitmate/metrics.db.
• Monthly Spend & Budget Cap Enforcement: Checks monthly spend against configured budget_cap_usd, halting with exit code 1 if exceeded and issuing early warning at 80% threshold.
• gitmate stats CLI Command: Rich formatted table displaying total runs, cache hit rate, token counts, estimated spend, average latency (hit vs miss), and breakdowns by command and model. Supports --days, --month, and --raw (JSON).
• Code Quality & Clean-up: Exposes public .underlying property on CachedProvider replacing private _provider access across modules.

Verification

• 218 tests passing (100%), expanding test suite with 11 new Phase 6 tests.
• ruff check . clean, ruff format --check . clean, and mypy src tests (strict mode) clean.
• Manual verification of gitmate stats and gitmate stats --raw.