v0.2.0

What's changed

Decision logic: exponential time decay

Replaced the adaptive threshold system (which varied min-samples based on usage frequency) with exponential time decay. Approval rates now use a 7-day half-life — recent decisions carry more weight than old ones.

The key benefit: if you start rejecting an action you previously always approved, the weighted approval rate drops within days and Relay starts interrupting again. The system can no longer get permanently locked into auto-approve.

Changes

• Approval rate calculation uses per-record weights: weight = 0.5 ^ (age_days / 7)
• get_count now returns effective weight (sum of decayed weights) instead of raw record count
• Decision thresholds updated to effective-weight values: low-risk ≥ 4, medium-risk ≥ 7
• get_stats now reports decayed approval_rate and effective_weight, consistent with what the decision logic actually uses
• Removed get_active_days (no longer needed)