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/git-sync.module.ts

@@ -21,9 +21,10 @@ import { GitSyncController } from './git-sync.controller';
  *   - EnvironmentModule (global) — EnvironmentService config;
  *   - CollaborationModule — exports CollaborationGateway for native body writes;
  *   - PageModule — exports PageService for structural mutations;
- *   - ScheduleModule (NOT forRoot) — so @Interval is discovered. forRoot() is
- *     already registered globally by TelemetryModule; importing the plain module
- *     here avoids a duplicate scheduler registration (plan §6 note).
+ *   - ScheduleModule (NOT forRoot) — so SchedulerRegistry is injectable (the
+ *     orchestrator registers a DYNAMIC poll interval in onModuleInit). forRoot()
+ *     is already registered globally by TelemetryModule; importing the plain
+ *     module here avoids a duplicate scheduler registration (plan §6 note).
  *
  * RedisService is provided by the global RedisModule (app.module) and CASL's
  * WorkspaceAbilityFactory by the global CaslModule — both resolve without an