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>

docs/SPEC.md

@@ -162,6 +162,15 @@ the actual findings plus matched reference facts from a curated, exact-match kno
 ("RAG-lite" — no embeddings/vector store, stdlib only); no fine-tuning. HTTP via stdlib `urllib`
 (no new core dependency); output is advisory (consistent with D9).
 
+### M15 — Logging & report bundles (D25)
+Opt-in (one `logging_enabled` toggle, default off). When on: the application logs to a rotating
+`app.log`, and **each diagnostic is stored in its own directory** (capture log, structured
+result, human-readable report, scoped game logs, and a record of every AI interaction — the
+exact data sent, the model, and its reply). A **Report** action zips one diagnostic's directory
+(plus the app log) into a shareable bundle saved under the reports folder (GUI button; CLI
+`rigdoctor bundle`). Everything stays local — a report only leaves the machine if the user
+shares the zip. Stdlib only (`logging` + `zipfile`).
+
 ## 5. Non-functional requirements
 - **Zero hard deps for the core/CLI/daemon** — Python stdlib + tools already present. **Qt
   (PySide6) is required only by the GUI (M10) and tray (M11) modules**, declared in the