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

docs/DECISIONS.md

@@ -264,9 +264,21 @@ root cause + suggested next steps). Adds M14 to the D14 set.
   as suggestions (consistent with D9 — it explains/recommends, applying fixes stays
   consent-gated). No new runtime dependency (HTTP via stdlib).
 
+### D25 — Logging & report bundles (M15) — *DECIDED 2026-05-22*
+Opt-in logging + shareable diagnostic reports.
+- **One combined `logging_enabled` toggle** (default off) controls both application logging
+  (rotating `app.log`) and per-diagnostic storage. Kept as a single switch for simplicity.
+- **Each diagnostic is stored in its own directory** (`DATA_DIR/diagnostics/<id>/`): capture
+  log, structured `result.json`, human-readable `report.txt`, a scoped game-log snapshot, and an
+  `ai/` folder recording each AI interaction (**exact data sent, provider+model, and the reply**).
+- **"Report"** zips one diagnostic directory (plus `app.log`) into `DATA_DIR/reports/` —
+  auto-saved there (no save dialog), shown with its path. Available only when logging is on
+  (nothing is stored otherwise). CLI: `rigdoctor bundle`.
+- Everything stays local; the report only leaves the machine if the user shares the zip.
+
 ## Open
 
-None currently — all tracked decisions (D1–D24) are resolved. New questions will be added
+None currently — all tracked decisions (D1–D25) are resolved. New questions will be added
 here as they arise. Remaining detail to flesh out during build: the tray's supporting-action
 set (D13), per-module apt package names, M12's tunnel/token specifics, and M13's
 update mechanism (APT repo vs. self-installed `.deb`).

docs/MODULES.md

@@ -2,7 +2,8 @@
 
 Status: ⬜ not started · 🟦 designing · 🟨 in progress · ✅ done
 
-> Module set per D14, plus **M12 (session sharing, D16)** and **M13 (auto-update, D18)**.
+> Module set per D14, plus **M12 (session sharing, D16)**, **M13 (auto-update, D18)**,
+> **M14 (AI assistant, D24)**, and **M15 (logging & reports, D25)**.
 > **M7 (stress/repro) was dropped (D7).** M10/M11 are the GUI and tray modules (D10/D11).
 > GPU scope reads "all (NVIDIA first)" — NVIDIA first, others via the vendor abstraction (D4).
 
@@ -21,6 +22,7 @@ Status: ⬜ not started · 🟦 designing · 🟨 in progress · ✅ done
 | M12 | Session sharing (shared terminal) | Sharing | none (relay) | all | P3 | ✅ |
 | M13 | Auto-update | (core) | none (stdlib; user-local file swap) | all | P3 | ✅ |
 | M14 | AI assistant (explain diagnostics) | (optional) | none (stdlib urllib; Ollama or Claude) | all | P3 | ✅ |
+| M15 | Logging & report bundles | (core) | none (stdlib logging + zip) | all | P3 | ✅ |
 | ~~M7~~ | ~~Stress / repro~~ | — | — | — | — | ❌ dropped (D7) |
 
 ## Notes per module
@@ -128,6 +130,13 @@ Status: ⬜ not started · 🟦 designing · 🟨 in progress · ✅ done
   which lifts a small local model and sharpens Claude. Stdlib `urllib` (no pip deps); output is
   advisory (D9). Configure in **Settings → AI assistant**.
 
+- **M15 Logging & report bundles** (D25) — opt-in via one `logging_enabled` toggle (default off):
+  application logging to a rotating `app.log` (`core/applog.py`) and **per-diagnostic storage**
+  (`core/diagstore.py`) — each diagnostic gets its own `DATA_DIR/diagnostics/<id>/` (capture,
+  `result.json`, `report.txt`, scoped game logs, and an `ai/` record of every AI interaction:
+  exact data sent, model, reply). **"Report"** zips one into `DATA_DIR/reports/` (GUI button on
+  the diagnostic dialog; CLI `rigdoctor bundle`). Stays local; shareable on demand.
+
 ## Bundles (final — D14)
 - **Essential:** M1 + M3 + M4  *(the MVP, NVIDIA-only — D5)*
 - **Monitoring:** M2 + M8

docs/ROADMAP.md

@@ -97,6 +97,13 @@ Ubuntu + NVIDIA first; `.deb` distribution (see `DECISIONS.md`).
 - [ ] *Possible follow-ups:* interactive chat grounded in the data; more reference-KB entries;
       an "Explain" button on the System Health page.
 
+## Phase 8 — Logging & report bundles  (M15, D25)
+- [x] **Opt-in logging** (one `logging_enabled` toggle): rotating `app.log` (`core/applog.py`)
+      + **per-diagnostic storage** in its own directory (`core/diagstore.py`) — capture,
+      result, report, scoped game logs, and AI-interaction records.
+- [x] **Report** bundle — zip a diagnostic (incl. exactly what was sent to the AI, the model,
+      and its reply) into the reports folder. GUI button + `rigdoctor bundle`.
+
 > **Out of scope:** stress/repro module (D7); multi-distro support and packaging beyond
 > Ubuntu/apt + `.deb` (D15) — a thin seam is kept but not built out.
 

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

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "rigdoctor"
-version = "0.29.0"
+version = "0.30.0"
 description = "Modular hardware monitoring & crash diagnostics for Linux gamers."
 readme = "README.md"
 requires-python = ">=3.11"

src/rigdoctor/__init__.py

@@ -1,3 +1,3 @@
 """RigDoctor — modular hardware monitoring & crash diagnostics for Linux gamers."""
 
-__version__ = "0.29.0"
+__version__ = "0.30.0"

src/rigdoctor/cli.py

@@ -472,6 +472,23 @@ def cmd_ai(args) -> int:
     return 0 if ok else 1
 
 
+def cmd_bundle(args) -> int:
+    """Zip the latest stored diagnostic into a report bundle (M15) — needs logging enabled."""
+    from .core import diagstore
+
+    if not diagstore.enabled():
+        print("Logging is off. Enable it (Settings → Logging, or set logging_enabled) so "
+              "diagnostics are stored and can be reported.")
+        return 1
+    directory = diagstore.latest_dir()
+    if directory is None:
+        print("No stored diagnostics yet — run a diagnostic first.")
+        return 1
+    out = diagstore.make_report(directory)
+    print(f"Report written: {out}")
+    return 0
+
+
 def cmd_gameenv(args) -> int:
     from dataclasses import asdict
 
@@ -686,10 +703,16 @@ def build_parser() -> argparse.ArgumentParser:
     ai_sub.add_parser("test", help="send a tiny probe to verify connectivity").set_defaults(func=cmd_ai)
     ai_sub.add_parser("explain", help="explain the current health findings with AI").set_defaults(func=cmd_ai)
     ai_p.set_defaults(func=cmd_ai, ai_cmd=None)
+
+    bundle_p = sub.add_parser("bundle", help="zip the latest stored diagnostic into a report bundle (M15)")
+    bundle_p.set_defaults(func=cmd_bundle)
     return p
 
 
 def main(argv: list[str] | None = None) -> int:
+    from .core import applog
+
+    applog.setup()  # opt-in app logging (M15); no-op unless logging_enabled
     args = build_parser().parse_args(argv)
     return args.func(args)
 

src/rigdoctor/config.py

@@ -37,6 +37,12 @@ SPAWN_LOG = STATE_DIR / "recorder.out"
 # not config: refreshed by the background scan on every launch).
 GAMES_FILE = STATE_DIR / "games.json"
 
+# Logging & reports (opt-in via `logging_enabled`). App log: rotating file of app events.
+# Each diagnostic is stored under DIAGNOSTICS_DIR/<id>/; "Report" zips one into REPORTS_DIR.
+APP_LOG = STATE_DIR / "app.log"
+DIAGNOSTICS_DIR = DATA_DIR / "diagnostics"
+REPORTS_DIR = DATA_DIR / "reports"
+
 # Update access token (M13) — gates updates to Gitea account holders (D18).
 # Stored in the OS keyring (Secret Service / GNOME Keyring) via `secret-tool` when
 # available — encrypted at rest, unlocked with the login session — else a 0600 file.
@@ -190,6 +196,7 @@ DEFAULTS: dict = {
     "ai_provider": "",            # AI assistant (M14, D24): "" (unset) | "ollama" | "claude"
     "ai_model": "",               # model name (e.g. "llama3.1" for Ollama; blank = Claude default)
     "ai_endpoint": "http://localhost:11434",  # Ollama server base URL (Claude uses a fixed endpoint)
+    "logging_enabled": False,     # opt-in: app logging + per-diagnostic storage + Report (M15)
 }
 
 

src/rigdoctor/core/applog.py

@@ -0,0 +1,63 @@
+"""Application logging (M15) — opt-in via the `logging_enabled` setting.
+
+When enabled, app events/errors are written to a rotating file (`config.APP_LOG`); when
+disabled, nothing is written (no file is created). All RigDoctor code logs through
+``applog.get_logger(__name__)``; the handler is attached once at startup by :func:`setup`.
+Stdlib ``logging`` only.
+"""
+
+from __future__ import annotations
+
+import logging
+from logging.handlers import RotatingFileHandler
+
+from .. import config
+
+_ROOT = "rigdoctor"
+_configured = False
+
+
+def setup(force: bool = False) -> bool:
+    """Attach the file handler if logging is enabled. Idempotent. Returns whether it's on."""
+    global _configured
+    logger = logging.getLogger(_ROOT)
+    enabled = bool(config.load_config().get("logging_enabled", False))
+
+    if not enabled:
+        if force:  # toggled off at runtime — detach so we stop writing
+            for h in list(logger.handlers):
+                logger.removeHandler(h)
+                h.close()
+            _configured = False
+        return False
+
+    if _configured and not force:
+        return True
+    for h in list(logger.handlers):  # avoid duplicate handlers on re-setup
+        logger.removeHandler(h)
+        h.close()
+    try:
+        config.STATE_DIR.mkdir(parents=True, exist_ok=True)
+        handler = RotatingFileHandler(config.APP_LOG, maxBytes=2_000_000, backupCount=3,
+                                      encoding="utf-8")
+        handler.setFormatter(logging.Formatter(
+            "%(asctime)s %(levelname)-7s %(name)s: %(message)s"))
+        logger.addHandler(handler)
+        logger.setLevel(logging.INFO)
+        logger.propagate = False
+        _configured = True
+        logger.info("logging started (rigdoctor %s)", _version())
+    except OSError:
+        return False
+    return True
+
+
+def get_logger(name: str) -> logging.Logger:
+    """A child logger. Safe to call before setup — it just won't write until enabled."""
+    short = name.split(".")[-1]
+    return logging.getLogger(f"{_ROOT}.{short}")
+
+
+def _version() -> str:
+    from .. import __version__
+    return __version__

src/rigdoctor/core/diagnostic.py

@@ -28,6 +28,7 @@ class DiagnosticResult:
     game: str | None
     summary: Summary           # capture window: peak temps/power, events, last samples (M3)
     findings: list[Finding]    # health findings: Xid/SMART/driver/etc. (M4)
+    dir: str | None = None     # storage directory when logging is on (M15); else None
 
 
 @dataclass
@@ -97,7 +98,22 @@ def finish(last_n: int = 10, log_path=None) -> DiagnosticResult:
     summary = summarize(path, last_n=last_n)
     game = _game_from_summary(summary) or (reccontrol.read_status() or {}).get("game")
     findings = run_health_checks()
-    return DiagnosticResult(game=game, summary=summary, findings=findings)
+    result = DiagnosticResult(game=game, summary=summary, findings=findings)
+    _store(result, path, summary)
+    return result
+
+
+def _store(result: DiagnosticResult, capture_path, summary: Summary) -> None:
+    """Persist the diagnostic to its own directory when logging is enabled (M15)."""
+    try:
+        from . import diagstore
+
+        since = (summary.start - 60) if summary.start else None
+        directory = diagstore.store(result, capture_path, since=since)
+        if directory:
+            result.dir = str(directory)
+    except Exception:  # storage must never break a diagnostic
+        pass
 
 
 # --- hard-crash detection & post-crash analysis -----------------------------------
@@ -184,4 +200,6 @@ def analyze_crash(last_n: int = 15) -> DiagnosticResult:
     findings += check_previous_boot()                       # the crashed boot's kernel log
     findings += run_health_checks(include_journal=False)    # SMART/driver/persistence/temps
     findings.sort(key=lambda f: _SEV_ORDER.get(f.severity, 9))
-    return DiagnosticResult(game=_game_from_summary(summary), summary=summary, findings=findings)
+    result = DiagnosticResult(game=_game_from_summary(summary), summary=summary, findings=findings)
+    _store(result, _crash_path(), summary)
+    return result

src/rigdoctor/core/diagstore.py

@@ -0,0 +1,136 @@
+"""Per-diagnostic storage + Report bundles (M15) — opt-in via `logging_enabled`.
+
+When logging is on, each finished diagnostic is persisted to its own directory under
+``config.DIAGNOSTICS_DIR/<id>/`` (capture log, structured result, human-readable report, a
+game-log snapshot, and any AI interactions). "Report" zips one directory — including exactly
+**what was sent to the AI, which model, and its reply** — into ``config.REPORTS_DIR``.
+"""
+
+from __future__ import annotations
+
+import json
+import shutil
+import time
+import zipfile
+from dataclasses import asdict, is_dataclass
+from pathlib import Path
+
+from .. import config
+
+
+def enabled() -> bool:
+    return bool(config.load_config().get("logging_enabled", False))
+
+
+def _slug(name: str | None) -> str:
+    s = "".join(c if c.isalnum() else "-" for c in (name or "session").lower())
+    return s.strip("-")[:40] or "session"
+
+
+def _new_dir(game: str | None) -> Path:
+    base = config.DIAGNOSTICS_DIR
+    stamp = time.strftime("%Y%m%d-%H%M%S")
+    name = f"{stamp}-{_slug(game)}"
+    target = base / name
+    n = 1
+    while target.exists():
+        target = base / f"{name}-{n}"
+        n += 1
+    target.mkdir(parents=True, exist_ok=True)
+    return target
+
+
+def _as_dict(obj):
+    if is_dataclass(obj):
+        return asdict(obj)
+    return getattr(obj, "__dict__", {}) or str(obj)
+
+
+def store(result, capture_path=None, since: float | None = None) -> Path | None:
+    """Persist a finished diagnostic to its own directory. Returns the dir, or None if off."""
+    if not enabled():
+        return None
+    from ..render import render_summary
+    from . import ai, gamelogs
+
+    target = _new_dir(getattr(result, "game", None))
+
+    if capture_path and Path(capture_path).exists():
+        try:
+            shutil.copyfile(capture_path, target / "capture.jsonl")
+        except OSError:
+            pass
+
+    payload = {
+        "game": getattr(result, "game", None),
+        "stored_at": time.time(),
+        "summary": _as_dict(result.summary),
+        "findings": [_as_dict(f) for f in result.findings],
+    }
+    _write(target / "result.json", json.dumps(payload, indent=2, default=str))
+
+    report = [f"Game: {getattr(result, 'game', None) or 'unknown'}", "",
+              render_summary(result.summary), "",
+              ai.format_findings(result.findings, header="Findings:")]
+    _write(target / "report.txt", "\n".join(report))
+
+    try:
+        logs = gamelogs.collect(since=since)
+        if logs:
+            _write(target / "gamelogs.txt", logs)
+    except OSError:
+        pass
+    return target
+
+
+def record_ai(diag_dir, *, provider: str, model: str, system: str, prompt: str, response: str) -> None:
+    """Save one AI interaction (exact data sent, model, reply) into the diagnostic's `ai/` dir."""
+    if not diag_dir:
+        return
+    out = Path(diag_dir) / "ai"
+    try:
+        out.mkdir(parents=True, exist_ok=True)
+    except OSError:
+        return
+    stamp = time.strftime("%Y%m%d-%H%M%S")
+    record = {
+        "timestamp": time.time(), "provider": provider, "model": model,
+        "system_prompt": system, "data_sent_to_model": prompt, "model_reply": response,
+    }
+    _write(out / f"explain-{stamp}.json", json.dumps(record, indent=2, default=str))
+    readable = (
+        f"Provider: {provider}\nModel:    {model}\n\n"
+        f"=== System prompt ===\n{system}\n\n"
+        f"=== Data sent to the model ===\n{prompt}\n\n"
+        f"=== Model reply ===\n{response}\n"
+    )
+    _write(out / f"explain-{stamp}.txt", readable)
+
+
+def make_report(diag_dir) -> Path:
+    """Zip a diagnostic directory (plus the app log) into REPORTS_DIR; return the zip path."""
+    diag_dir = Path(diag_dir)
+    config.REPORTS_DIR.mkdir(parents=True, exist_ok=True)
+    out = config.REPORTS_DIR / f"report-{diag_dir.name}.zip"
+    with zipfile.ZipFile(out, "w", zipfile.ZIP_DEFLATED) as zf:
+        for path in sorted(diag_dir.rglob("*")):
+            if path.is_file():
+                zf.write(path, arcname=str(Path(diag_dir.name) / path.relative_to(diag_dir)))
+        if config.APP_LOG.exists():  # the application log, for context around the session
+            zf.write(config.APP_LOG, arcname=str(Path(diag_dir.name) / "app.log"))
+    return out
+
+
+def latest_dir() -> Path | None:
+    try:
+        dirs = [d for d in config.DIAGNOSTICS_DIR.iterdir() if d.is_dir()]
+    except OSError:
+        return None
+    return max(dirs, key=lambda d: d.stat().st_mtime) if dirs else None
+
+
+def _write(path: Path, text: str) -> None:
+    try:
+        path.write_text(text, encoding="utf-8")
+    except OSError:
+        pass

src/rigdoctor/gui/app.py

@@ -17,6 +17,10 @@ ICON = Path(__file__).parent / "assets" / "rigdoctor.svg"
 
 
 def main(argv: list[str] | None = None) -> int:
+    from ..core import applog
+
+    applog.setup()  # opt-in app logging (M15); no-op unless logging_enabled
+    applog.get_logger(__name__).info("GUI starting")
     desktop.ensure()  # self-register icon + .desktop so updates show it without re-installing
     app = QApplication(argv if argv is not None else sys.argv)
     app.setApplicationName("RigDoctor")

src/rigdoctor/gui/diagnostic_dialog.py

@@ -86,6 +86,10 @@ class DiagnosticDialog(QDialog):
         from ..core import ai
         self._explain_btn.setVisible(ai.is_configured())  # opt-in only; hidden if not set up
         buttons.addWidget(self._explain_btn)
+        self._report_btn = QPushButton("Report")  # zip this diagnostic's logs (M15)
+        self._report_btn.clicked.connect(self._make_report)
+        self._report_btn.setVisible(bool(result.dir))  # only when logging stored the session
+        buttons.addWidget(self._report_btn)
         buttons.addStretch(1)
         close = QPushButton("Close")
         close.setObjectName("PrimaryButton")
@@ -135,7 +139,15 @@ class DiagnosticDialog(QDialog):
         logs = gamelogs.collect(since=since)  # scoped to this session
         if logs:
             lines.append("\nGame/Proton/Steam logs for this session:\n" + logs)
-        self._explained.emit(ai.explain("\n".join(lines)))
+        text = "\n".join(lines)
+        ok, reply = ai.explain(text)
+        if result.dir:  # record exactly what was sent, the model, and the reply (M15)
+            from ..core import diagstore
+            diagstore.record_ai(
+                result.dir, provider=ai.provider(), model=ai.model(),
+                system=ai.SYSTEM_PROMPT, prompt=ai.build_prompt(text),
+                response=reply if ok else f"[error] {reply}")
+        self._explained.emit((ok, reply))
 
     def _on_explained(self, result) -> None:
         ok, text = result
@@ -143,6 +155,31 @@ class DiagnosticDialog(QDialog):
         self._explain_btn.setText("Explain with AI")
         self._show_explanation(text if ok else f"AI explanation failed:\n\n{text}")
 
+    # --- Report bundle (M15) ------------------------------------------------------
+    def _make_report(self) -> None:
+        from PySide6.QtCore import QUrl
+        from PySide6.QtGui import QDesktopServices
+
+        from ..core import diagstore
+
+        self._report_btn.setEnabled(False)
+        try:
+            out = diagstore.make_report(self._result.dir)
+        except OSError as exc:
+            self._report_btn.setEnabled(True)
+            QMessageBox.warning(self, "Report failed", str(exc))
+            return
+        self._report_btn.setEnabled(True)
+        box = QMessageBox(self)
+        box.setWindowTitle("Report created")
+        box.setText(f"Saved report:\n{out}\n\nIt contains this diagnostic's logs and any AI "
+                    "interaction (data sent, model, and reply).")
+        open_btn = box.addButton("Open folder", QMessageBox.ButtonRole.ActionRole)
+        box.addButton("OK", QMessageBox.ButtonRole.AcceptRole)
+        box.exec()
+        if box.clickedButton() is open_btn:
+            QDesktopServices.openUrl(QUrl.fromLocalFile(str(out.parent)))
+
     def _show_explanation(self, text: str) -> None:
         from ..core import ai
 

src/rigdoctor/gui/setup_page.py

@@ -215,6 +215,23 @@ class SetupPage(QWidget):
         ai_layout.addWidget(self._ai_status)
         root.addWidget(ai_card)
 
+        # Logging (M15): opt-in app logging + per-diagnostic storage (enables the Report bundle).
+        log_card, log_layout = _panel("Logging")
+        log_desc = QLabel(
+            "Save application logs and store each diagnostic in its own folder so you can review "
+            "or <b>Report</b> it. Off by default; everything stays on your machine.\n"
+            f"•  Diagnostics: {config.DIAGNOSTICS_DIR}\n"
+            f"•  Reports: {config.REPORTS_DIR}"
+        )
+        log_desc.setObjectName("Muted")
+        log_desc.setWordWrap(True)
+        log_layout.addWidget(log_desc)
+        self._logging = QCheckBox("Enable logging (application + diagnostics)")
+        self._logging.setChecked(config.load_config().get("logging_enabled", False))
+        self._logging.toggled.connect(self._toggle_logging)
+        log_layout.addWidget(self._logging)
+        root.addWidget(log_card)
+
         # Account access (M13/M12): one Gitea token gates updates and session sharing.
         upd_card, upd_layout = _panel("Account access")
         hint = QLabel("A Gitea access token unlocks updates and session sharing. "
@@ -320,6 +337,12 @@ class SetupPage(QWidget):
         self._ai_test_btn.setEnabled(True)
         self._ai_status.setText(("✓ " if ok else "✗ ") + (msg[:200] if msg else ""))
 
+    def _toggle_logging(self, on: bool) -> None:
+        from ..core import applog
+
+        config.update_config(logging_enabled=on)
+        applog.setup(force=True)  # attach/detach the file handler immediately
+
     def _run_wizard(self) -> None:
         from .setup_wizard import SetupWizard
 

tests/test_diagstore.py

@@ -0,0 +1,100 @@
+"""Tests for M15 per-diagnostic storage + Report bundles + app logging."""
+
+import json
+import tempfile
+import unittest
+import zipfile
+from dataclasses import dataclass, field
+from pathlib import Path
+from unittest import mock
+
+from rigdoctor.core import applog, diagstore
+
+
+@dataclass
+class FakeSummary:
+    start: float = 1.0
+    end: float = 2.0
+    samples: int = 3
+    events: list = field(default_factory=list)
+
+
+@dataclass
+class FakeFinding:
+    severity: str = "ok"
+    category: str = "GPU"
+    title: str = "Looks fine"
+    detail: str = "no issues"
+
+
+@dataclass
+class FakeResult:
+    game: str = "Path of Exile 2"
+    summary: FakeSummary = field(default_factory=FakeSummary)
+    findings: list = field(default_factory=lambda: [FakeFinding()])
+    dir: str | None = None
+
+
+class StoreTests(unittest.TestCase):
+    def setUp(self):
+        self.tmp = Path(tempfile.mkdtemp())
+
+    def test_disabled_returns_none(self):
+        with mock.patch.object(diagstore, "enabled", return_value=False):
+            self.assertIsNone(diagstore.store(FakeResult()))
+
+    def test_store_writes_artifacts(self):
+        with mock.patch.object(diagstore, "enabled", return_value=True), \
+             mock.patch("rigdoctor.render.render_summary", return_value="SUMMARY-TEXT"), \
+             mock.patch("rigdoctor.core.gamelogs.collect", return_value="LOG-TEXT"), \
+             mock.patch.object(diagstore.config, "DIAGNOSTICS_DIR", self.tmp / "diagnostics"):
+            directory = diagstore.store(FakeResult())
+        self.assertTrue((directory / "result.json").exists())
+        self.assertTrue((directory / "report.txt").exists())
+        self.assertEqual((directory / "gamelogs.txt").read_text(), "LOG-TEXT")
+        data = json.loads((directory / "result.json").read_text())
+        self.assertEqual(data["game"], "Path of Exile 2")
+        self.assertEqual(len(data["findings"]), 1)
+
+    def test_record_ai_then_report_includes_ai_and_applog(self):
+        diag = self.tmp / "20260522-poe2"
+        diag.mkdir()
+        diagstore.record_ai(diag, provider="claude", model="claude-opus-4-7",
+                            system="SYS", prompt="EXACT DATA SENT", response="THE REPLY")
+        ai_files = list((diag / "ai").glob("explain-*.json"))
+        self.assertTrue(ai_files)
+        record = json.loads(ai_files[0].read_text())
+        self.assertEqual(record["model"], "claude-opus-4-7")
+        self.assertEqual(record["data_sent_to_model"], "EXACT DATA SENT")
+        self.assertEqual(record["model_reply"], "THE REPLY")
+
+        app_log = self.tmp / "app.log"
+        app_log.write_text("app log line")
+        with mock.patch.object(diagstore.config, "REPORTS_DIR", self.tmp / "reports"), \
+             mock.patch.object(diagstore.config, "APP_LOG", app_log):
+            out = diagstore.make_report(diag)
+        self.assertTrue(out.exists())
+        with zipfile.ZipFile(out) as zf:
+            names = zf.namelist()
+        self.assertTrue(any(n.endswith("app.log") for n in names))
+        self.assertTrue(any("/ai/explain-" in n for n in names))
+
+
+class AppLogTests(unittest.TestCase):
+    def test_disabled_is_noop(self):
+        with mock.patch.object(applog.config, "load_config", return_value={"logging_enabled": False}):
+            self.assertFalse(applog.setup(force=True))
+
+    def test_enabled_writes_file(self):
+        tmp = Path(tempfile.mkdtemp())
+        with mock.patch.object(applog.config, "load_config", return_value={"logging_enabled": True}), \
+             mock.patch.object(applog.config, "STATE_DIR", tmp), \
+             mock.patch.object(applog.config, "APP_LOG", tmp / "app.log"):
+            self.assertTrue(applog.setup(force=True))
+            applog.get_logger("test").info("hello world")
+            applog.setup(force=True)  # cleanup path: re-run detaches/reattaches cleanly
+        self.assertTrue((tmp / "app.log").exists())
+
+
+if __name__ == "__main__":
+    unittest.main()