chore: bump version to 0.5.28

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

Release v0.5.27

feat: add default exclude patterns, env var fallbacks, and richer met…

…rics

- Default exclude patterns for lock files, minified assets, generated code,
  and vendor directories so reviews focus on meaningful changes
- Env var fallbacks for GITHUB_TOKEN and DIFFSCOPE_WEBHOOK_SECRET in config
- Token usage metrics (total, prompt, completion) for cost tracking
- Labeled metrics for comment severity and category breakdowns

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: move audit.toml to .cargo/ for cargo-audit discovery

cargo-audit looks for config at .cargo/audit.toml, not the project root.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: resolve clippy warnings (for_kv_map, unnecessary_map_or)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: cast PG aggregate results to correct types for sqlx decoding

AVG() returns NUMERIC in PostgreSQL which is incompatible with f64 in
sqlx. Cast AVG results to FLOAT8 and fix PERCENTILE_CONT parentheses.
Also fix WHERE clause for by_repo query when no time filters are set.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Copy migrations directory in Dockerfile for sqlx::migrate!() macro

The sqlx::migrate!() macro embeds migrations at compile time and
requires the migrations directory to exist during cargo build.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Fix TypeScript build errors in Admin.tsx

Remove unused imports (TrendingUp, TrendingDown, Clock) and fix
Recharts tooltip formatter type to accept ValueType.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Add Events and Admin pages for wide event visualization

Events page: full Ensemble-style review event viewer with stat cards,
duration/token timeline charts, filterable/sortable event table with
expandable detail rows showing per-file waterfall, hotspots, and pass
breakdown.

Admin page: system-wide analytics dashboard with usage metrics, model
breakdown table, repository activity charts, error rate monitoring,
latency percentiles (p50/p95/p99), and slow file outliers.

Backend: add /api/events endpoint returning ReviewEvent objects with
source/model/status filtering.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Enrich wide event pipeline with full AI reviewer telemetry

Wire token usage from LLM adapters through ReviewResult to ReviewEvent
and the frontend. Add per-file metrics (latency, tokens, comment count),
hotspot risk scoring, convention suppression counts, and per-pass comment
breakdowns. Extend ReviewEventBuilder and EventPanel UI to surface all
new telemetry data.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>