chore: bump version to 0.9.0

[decko]

Summary

Release v0.9.0 — 4 features, 2 bug fixes.

Features

• JSONL history log (feat: JSONL history log for cross-run tracking #170) — .raki/history.jsonl appended after every raki run
• raki trends (feat: raki trends — metric trajectories over time #171) — metric trajectories with sparklines and trend indicators
• Judge config in reports (feat: serialize judge config fields into report JSON #173) — llm_provider, llm_model, llm_temperature, llm_max_tokens
• Diff judge warnings (feat: warn when judge configs differ in --diff comparison #187) — warns when judge configs differ between compared reports

Bug Fixes

• Google silent-zero fix (bug: Google judge provider produces silent 0.0 scores (instructor #1658) #169) — detect and skip instructor#1658 silent scores
• Alcove rework detection (Alcove adapter: hardcoded rework_cycles=0, findings=[], and single phase #176) — transcript-based rework cycle and phase detection

Release checklist

• 1136 tests pass
• Lint clean
• Verified against real SODA session data (15 sessions + 6 alcove)
• Changelog generated via towncrier
• Version bumped in both pyproject.toml and init.py

Co-Authored-By: Claude Opus 4.6 (1M context) noreply@anthropic.com