fix(git-sync): address review — configurable poll, always-on loop-guard, cleanup

Comprehensive-review follow-ups (APPROVE WITH SUGGESTIONS; no critical issues):
- poll interval is now actually configurable: replaced the hardcoded
  @Interval('git-sync-poll', 15000) with a dynamic SchedulerRegistry interval
  registered in onModuleInit from getGitSyncPollIntervalMs() (cleared in
  onModuleDestroy); /status and the real cadence now share one config source.
  Boots logging 'poll interval registered (Nms)'.
- loop-guard now ALWAYS applies: the lastUpdatedSource==='git-sync' skip was
  nested inside the !spaceId/!workspaceId branch, so structural self-writes
  (CREATE/MOVE/RESTORE/SOFT_DELETE, which carry spaceId+workspaceId) bypassed it
  and re-triggered cycles. Fetch the page row once, guard unconditionally, then
  resolve space/workspace.
- remove the dead PAGE_CONTENT_UPDATED subscription (it's a BullMQ job, never an
  EventEmitter event; body edits arrive via PAGE_UPDATED).
- fix the stale datasource comment (PageService DOES stamp 'git-sync' now).
- env getters: parseInt radix 10 + NaN/<=0 fallback for poll/debounce (+ max
  deletes), with 6 new environment.service.spec tests.

tsc clean; jest 723 pass; live cycle re-verified post-refactor (ran, push
applied, unflagged 92-page space untouched).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/server/src/integrations/git-sync/services/gitmost-datasource.service.ts

@@ -30,14 +30,12 @@ export interface GitSyncBindContext {
 }
 
 /**
- * The git-sync provenance carried into PageService writes. PageService stamps
- * `lastUpdatedSource = 'agent'` only when `provenance.actor === 'agent'`; for any
- * other actor it leaves the column at its default ('user'). So create/move/rename
- * through PageService DO NOT yet stamp 'git-sync' on the page row — see the note
- * in the report. Body writes (writeBody, §3.3) DO stamp 'git-sync' because the
- * collab context's `actor: 'git-sync'` flows into PersistenceExtension. We pass a
- * 'git-sync' provenance anyway so that when PageService is extended to honor it,
- * the marker propagates without touching the datasource.
+ * The git-sync provenance carried into PageService writes. PageService.create/
+ * update/movePage honor this provenance and stamp `lastUpdatedSource = 'git-sync'`
+ * on the page row when `provenance.actor === 'git-sync'`. Body writes (writeBody,
+ * §3.3) likewise stamp 'git-sync' because the collab context's `actor: 'git-sync'`
+ * flows into PersistenceExtension. So ALL git-sync structural + body writes mark
+ * the row's source, which the listener's loop-guard reads to skip our own writes.
  */
 const GIT_SYNC_PROVENANCE: AuthProvenanceData = {
   actor: 'git-sync',