feat(m15): opt-in logging + per-diagnostic storage + Report bundles — 0.30.0

One `logging_enabled` toggle (default off) gates everything (D25):
- core/applog.py: rotating app.log (no-op unless enabled); setup() at GUI/CLI start.
- core/diagstore.py: each diagnostic stored in DATA_DIR/diagnostics/<id>/ (capture,
  result.json, report.txt, scoped gamelogs, ai/ records of exactly what was sent to
  the model + which model + the reply). make_report() zips a diagnostic (+ app.log)
  into DATA_DIR/reports/.
- diagnostic.finish()/analyze_crash() store when enabled; DiagnosticResult.dir.
- GUI: Settings → Logging toggle; "Report" button on the diagnostic dialog; AI
  interactions recorded into the diagnostic dir on "Explain with AI".
- CLI: `rigdoctor bundle` (report is taken by the M4 health report).
- Tests for store/record_ai/make_report + applog gating; docs (D25, M15, Phase 8).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,17 @@ All notable changes to RigDoctor are recorded here. Format follows
 (`MAJOR.MINOR.PATCH`, pre-1.0). `__version__` and `pyproject.toml` must match the git
 release tag (so the auto-updater, D18, can compare versions).
 
+## [0.30.0] - 2026-05-22
+### Added
+- **Logging & report bundles (M15, D25)** — opt-in via one **Settings → Logging** toggle
+  (default off). When on: the app logs to a rotating `app.log`, and **each diagnostic is stored
+  in its own folder** (`~/.local/share/rigdoctor/diagnostics/<id>/`) with the capture log, a
+  structured `result.json`, a readable `report.txt`, a session-scoped game-log snapshot, and an
+  `ai/` record of every AI interaction — **the exact data sent, which model, and its reply**.
+- **Report** — a button on the diagnostic dialog (and `rigdoctor bundle`) zips a diagnostic's
+  folder plus `app.log` into `~/.local/share/rigdoctor/reports/<id>.zip` for sharing. Everything
+  stays local; the zip only leaves your machine if you share it. Available only when logging is on.
+
 ## [0.29.0] - 2026-05-22
 ### Added
 - **AI now resolves Steam app IDs from your library instead of guessing.** When app IDs appear