fix(sync): count disjoint-merge ops in localWinOpsCreated

autoResolveConflictsLWW returned only newLocalWinOps.length, excluding the
synthesized merged ops appended in STEP 3b. A sync whose only conflicts were
disjoint-field merges returned 0, so the caller (immediate-upload.service.ts)
skipped the immediate re-upload and reported IN_SYNC while the merged op sat
unsynced until a later cycle.

Count mergedResolutions.length too — each merge appends exactly one pending
local op. Mirrors the rejection-handler path (operation-log-sync.service.ts).
Add a regression spec asserting a merge-only conflict returns
localWinOpsCreated: 1 (fails on the old return, passes now).

Also harden the _corruptionSuspectedConflicts WeakSet doc against a future
refactor that clones EntityConflict between detect and resolve.

Addresses review feedback on PR #8874.

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

src/app/op-log/sync/conflict-resolution.disjoint-merge.spec.ts

@@ -188,6 +188,38 @@ describe('ConflictResolutionService — SPAP-14 disjoint-field merge', () => {
     expect((await journal.list('unreviewed')).length).toBe(0);
   });
 
+  // ── (a2) merge-only sync counts the synthesized op for re-upload ────────────
+  it('(a2) counts the synthesized merged op in localWinOpsCreated (drives re-upload)', async () => {
+    mockStore.select.and.returnValue(
+      of({ id: 'task-1', title: 'Local title', notes: 'base notes' }),
+    );
+
+    const localOp = op({
+      id: 'local-1',
+      clientId: 'A',
+      vectorClock: { A: 1 },
+      timestamp: 2000,
+      payload: { task: { id: 'task-1', changes: { title: 'Local title' } } },
+    });
+    const remoteOp = op({
+      id: 'remote-1',
+      clientId: 'B',
+      vectorClock: { B: 1 },
+      timestamp: 1000,
+      payload: { task: { id: 'task-1', changes: { notes: 'Remote notes' } } },
+    });
+
+    const result = await service.autoResolveConflictsLWW([
+      conflictOf([localOp], [remoteOp]),
+    ]);
+
+    // No LWW local-win ops here — the single synthesized merged op is the sole
+    // pending-local op. It MUST be counted or the caller's immediate re-upload
+    // is skipped and the sync falsely reports IN_SYNC while the merge is unsynced.
+    expect(mergedOpArgs()).toBeDefined();
+    expect(result.localWinOpsCreated).toBe(1);
+  });
+
   // ── (b) title vs title → LWW unchanged ─────────────────────────────────────
   it('(b) leaves same-field (title-vs-title) conflicts to LWW (journal unreviewed)', async () => {
     mockStore.select.and.returnValue(of({ id: 'task-1', title: 'Local title' }));

src/app/op-log/sync/conflict-resolution.service.ts

@@ -151,6 +151,12 @@ export class ConflictResolutionService {
    * same reference flows detection → autoResolveConflictsLWW), so a WeakSet
    * both avoids mutating the shared type and cannot leak across sync cycles.
    * Purely a side-channel: it never changes which op resolution picks.
+   *
+   * FRAGILE: attribution depends on the SAME EntityConflict reference surviving
+   * from detection (`.add`) to resolution (`.has`). A future refactor that
+   * clones or rebuilds the conflict object between those points would silently
+   * drop the `clock-corruption-suspected` classification (no error, just wrong
+   * journal reason). Keep the reference stable or switch to an explicit flag.
    */
   private readonly _corruptionSuspectedConflicts = new WeakSet<EntityConflict>();
 
@@ -597,7 +603,15 @@ export class ConflictResolutionService {
     const isValid = await this._validateAndRepairAfterResolution();
     if (!isValid) this.sessionValidation.setFailed();
 
-    return { localWinOpsCreated: newLocalWinOps.length };
+    // Count both LWW local-win ops AND disjoint-merge ops (STEP 3b): each merge
+    // appended a synthesized pending-local op that still needs uploading. The
+    // caller uses this count to trigger the immediate re-upload
+    // (immediate-upload.service.ts) — omitting merges lets a merge-only sync
+    // report IN_SYNC while its merged op sits unsynced until a later cycle.
+    // Mirrors the rejection-handler path (operation-log-sync.service.ts:361).
+    return {
+      localWinOpsCreated: newLocalWinOps.length + mergedResolutions.length,
+    };
   }
 
   /**