fix(git-sync): a malformed non-UUID gitmost_id no longer wedges a space's sync (C9-D1)

A vault file with a broken/hand-edited `gitmost_id` frontmatter (e.g.
`gitmost_id: [unclosed` or a non-uuid token) fed that value into a Postgres
`uuid` predicate (page update/delete), throwing 22P02 "invalid input syntax for
type uuid". The push apply recorded it as a per-cycle failure that never cleared —
refs never advance when failures>0, so the WHOLE space's sync looped on the same
failure indefinitely and no further legitimate change synced (found via web-test).

Wrap the id-scoped write ops (import/delete/move/rename/restore) at the bind()
seam: swallow exactly the 22P02 as an inert no-op so the cycle succeeds and the
rest of the space keeps syncing; re-throw anything else. pageId is the only
user-influenced uuid in these ops, so a 22P02 there unambiguously means it.

Verified on the stand: pushing a non-UUID gitmost_id now logs a skip warn and the
space stays at 0 failures (was 1 failure/cycle forever); a concurrent legit edit
to another page still syncs. Unit tests: import/delete swallow 22P02, non-22P02
re-throws. Full server suite green (2145).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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

@@ -418,6 +418,45 @@ describe('GitmostDataSourceService', () => {
     });
   });
 
+  // Bug C9-D1: a vault file with a malformed (non-UUID) `gitmost_id` frontmatter
+  // makes the id reach a Postgres `uuid` predicate, which throws error code
+  // '22P02'. Left unhandled the push apply records it as a per-cycle failure that
+  // never clears -> the whole space's sync loops forever. The bind() seam wraps the
+  // id-scoped writes so exactly that error is swallowed as an inert no-op.
+  describe('malformed-id guard (bug C9-D1: non-UUID gitmost_id must not wedge sync)', () => {
+    const pgInvalidUuid = Object.assign(
+      new Error('invalid input syntax for type uuid: "not-a-uuid"'),
+      { code: '22P02' },
+    );
+
+    it('importPageMarkdown swallows a 22P02 and does NOT write the body', async () => {
+      const { service, mocks } = build();
+      mocks.pageRepo.findById.mockRejectedValue(pgInvalidUuid);
+      const res = await service
+        .bind(CTX)
+        .importPageMarkdown('not-a-uuid', '# x');
+      expect(res).toEqual({}); // inert no-op, no throw
+      expect(mocks.collabGateway.writePageBody).not.toHaveBeenCalled();
+    });
+
+    it('deletePage swallows the 22P02 thrown by the uuid predicate (no wedge)', async () => {
+      const { service, mocks } = build();
+      // The malformed id reaches removePage's `uuid` predicate, which throws 22P02.
+      mocks.pageService.removePage.mockRejectedValue(pgInvalidUuid);
+      await expect(
+        service.bind(CTX).deletePage('not-a-uuid'),
+      ).resolves.toBeUndefined();
+    });
+
+    it('re-throws a NON-22P02 error (does not mask real failures)', async () => {
+      const { service, mocks } = build();
+      mocks.pageRepo.findById.mockRejectedValue(new Error('db down'));
+      await expect(
+        service.bind(CTX).importPageMarkdown('not-a-uuid', '# x'),
+      ).rejects.toThrow('db down');
+    });
+  });
+
   describe('createPage', () => {
     it('creates the shell with git-sync provenance, writes body, returns id', async () => {
       const { service, mocks } = build();