feat(m15): collect session-scoped system logs (kernel + coredumps) — 0.31.0

core/syslogs.py gathers, scoped to the diagnostic window:
- kernel-log slice (journalctl -k): Xid, OOM, MCE, PCIe AER, thermal, hung tasks
- crashed-process records (coredumpctl): exe, signal, when
Stored as syslogs.txt in the diagnostic dir, included in the Report bundle, and
fed to the AI on "Explain" alongside the game logs. Best-effort (degrades if the
tools are missing/denied); treats journalctl's "-- No entries --" as empty.
Tests + docs (M15/SPEC).

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

docs/SPEC.md

@@ -165,8 +165,10 @@ the actual findings plus matched reference facts from a curated, exact-match kno
 ### 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
+result, human-readable report, session-scoped **game logs** (Proton/Steam) and **system logs**
+(`journalctl -k` slice + `coredumpctl` crashed-process records), and a record of every AI
+interaction — the exact data sent, the model, and its reply). The collected logs are also fed to
+the AI on "Explain". System-log collection is best-effort (degrades if tools are missing/denied). 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`).