feat(app-dev): sync error hints, flatEntity labels, dev-mode summary UI, and docs (#21252)

Split out of #21240 — all remaining app-dev improvements. Stacked on
#21251 (review/merge that first).

- Actionable recovery hints on failed syncs; unified diff renderer;
`--dry-run` guard.
- Return `flatEntity` on update/delete sync actions and unify the diff
label.
- Summarize the dev-mode entity list unless `--verbose`.
- Docs: syncing & recovery guide + dry-run + open-an-issue prompt.
- Live execution mode for synced logic functions; clearer manifest
warnings.

<img width="1018" height="700" alt="image"
src="https://github.com/user-attachments/assets/5e9ce19e-0f1d-4f99-8524-4e118bde932b"
/>

packages/twenty-shared/src/constants/DocumentationPaths.ts

@@ -69,6 +69,8 @@ export const DOCUMENTATION_PATHS = {
     '/developers/extend/apps/operations/overview',
   DEVELOPERS_EXTEND_APPS_OPERATIONS_PUBLISHING:
     '/developers/extend/apps/operations/publishing',
+  DEVELOPERS_EXTEND_APPS_OPERATIONS_SYNC_AND_RECOVERY:
+    '/developers/extend/apps/operations/sync-and-recovery',
   DEVELOPERS_EXTEND_APPS_OPERATIONS_TESTING:
     '/developers/extend/apps/operations/testing',
   DEVELOPERS_EXTEND_OAUTH: '/developers/extend/oauth',