feat(state): opt-in auto-commit of state mutations (Phase 4)

settings.autoCommit — toggled from System › Auto-commit (self-gated on
the flake being a git repo) — makes every nomarchy-theme-sync apply/set
also git-commit theme-state.json in the downstream flake, so settings
history is `git log`. Off by default.

Design: the flag is live-read by the tool on each write (nothing in Nix
consumes it → instant toggle, no rebuild, no new option); the commit is
pathspec-limited to theme-state.json so unrelated dirty files are never
swept up; it fires when the flag is on before OR after the write, so
the disable-toggle itself lands in history; same-value writes no-op
(diff against HEAD); missing git identity falls back to
Nomarchy <nomarchy@localhost>; `bg next` is deliberately excluded.

Rider fix: `get` now prints booleans JSON-style (true, not Python's
True) — un-sticking the System menu's "Auto timezone (on/off)" label,
whose `= true` comparison could never match. All shell consumers
already normalise true|True, so no other behavior change.

Verified: V0 (py_compile, nix flake check) + V1 (HM generation builds,
generated nomarchy-menu passes bash -n, wiring present in the rendered
script) + a 7-assertion sandbox-repo round-trip covering enable/set/
same-value/disable/post-disable/apply paths and the identity fallback.
Remaining: on-machine check queued in agent/HARDWARE-QUEUE.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

agent/JOURNAL.md

@@ -17,6 +17,24 @@ Template:
 
 ---
 
+## 2026-07-04 — Opt-in auto-commit shipped (loop iteration #1)
+- **Task:** BACKLOG NOW#1 — auto-commit of state mutations (in-flake
+  state Phase 4). First autonomous /loop iteration.
+- **Did:** `settings.autoCommit` live-read by nomarchy-theme-sync;
+  pathspec-limited commit of theme-state.json on apply/set (fires if flag
+  on before OR after the write → the off-toggle commits too); identity
+  fallback; same-value no-op; `bg` excluded. Menu: System › Auto-commit
+  (instant, self-gated on `.git`). Rider: `get` prints booleans as JSON
+  `true`/`false`, fixing the stuck "Auto timezone (on/off)" menu label.
+  BACKLOG numbering switched to stable IDs (no renumbering).
+- **Verified:** V0 (py_compile, flake check) + V1 (HM generation builds;
+  generated menu `bash -n`) + a 7-assertion sandbox git-repo round-trip
+  (enable/set/same-value/disable/post-disable/apply/identity-fallback).
+- **Pending:** V3 queued in HARDWARE-QUEUE (on-machine toggle + apply).
+- **Next suggestion:** NOW#2 (CI checks-on-push) — but its runner half
+  may need Bernardo to register a Forgejo runner; deliver the workflow
+  regardless.
+
 ## 2026-07-04 — Backlog revision pass (human-requested)
 - **Task:** Bernardo asked for a philosophy-aligned revision of BACKLOG.md
   ("I'm sure I'm forgetting important items").