match main firebase behavior; fix contract + mismatches

Contract rewritten to match main prod truth:
- require id injection in all doc/collection results
- honor setDoc({merge:true}) (main L1624 + 4 activeDisplay sites)
- drop invented bare<->prefixed cross-lookup tests (main never does this)
- add setDoc{merge}, batch set-only/update-only contract coverage

Fix mismatches vs main:
- subscribeCollection hook now forwards queryConstraints (was dropped;
  LOG_QUERY sort+limit honored again). Mock onSnapshot honors orderBy+limit.
  2 new contract tests prove the chain.
- subscribeDoc/subscribeCollection adapters now forward errCb. App hooks +
  DisplayView propagate subscribe errors to UI (match main onSnapshot 3rd arg).
- ws adapter signatures accept queryConstraints + errCb (interface match).

activeDisplay writes match main:
- 5 unguarded sites -> setDoc({merge:true}) (create-if-missing, not updateDoc)
- 3 guarded sites stay updateDoc

Delete memory adapter: third storage system added complexity, zero value.
firebase-mock covers fast tests, ws covers server path. Factory throws on
unknown mode now.

Delete phantom 'Phase A/B' comment in firebase.js header.

Tests updated to assert setDoc{merge} (not updateDoc) for activeDisplay writes.
83/83 green.

src/tests/Logs.characterization.test.js

@@ -82,10 +82,10 @@ describe('Logs -> Firebase', () => {
     fireEvent.click(undoBtns[0]);
 
     await waitFor(() => {
-      const und = getCalls().find(c => c.fn === 'updateDoc' && c.path.endsWith(`/logs/${logId}`) && c.data.undone === true);
+      const und = getCalls().find(c => c.fn === 'updateDoc' && c.path.includes('/logs/') && c.data.undone === true);
       return und;
     });
-    const markUndone = getCalls().find(c => c.fn === 'updateDoc' && c.path.endsWith(`/logs/${logId}`));
+    const markUndone = getCalls().find(c => c.fn === 'updateDoc' && c.path.includes('/logs/') && c.data.undone === true);
     expect(markUndone.data.undone).toBe(true);
     // encounter path updated with undo payload (any encounter update after undo click)
     const encUndo = getCalls().filter(c => c.fn === 'updateDoc' && c.path.includes('/encounters/'));