diff --git a/.eslintrc.json b/.eslintrc.json
index bcc6d3615..8e2c0a637 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -25,8 +25,8 @@
       ],
       "plugins": ["@typescript-eslint", "prettier", "prefer-arrow", "local-rules"],
       "rules": {
-        "local-rules/require-hydration-guard": "warn",
-        "local-rules/require-entity-registry": "warn",
+        "local-rules/require-hydration-guard": "error",
+        "local-rules/require-entity-registry": "error",
         "@typescript-eslint/no-explicit-any": 0,
         "@typescript-eslint/ban-ts-comment": 0,
         "@typescript-eslint/no-empty-function": 0,
diff --git a/eslint-local-rules/rules/require-hydration-guard.js b/eslint-local-rules/rules/require-hydration-guard.js
index ea92e84fa..f165cd4e9 100644
--- a/eslint-local-rules/rules/require-hydration-guard.js
+++ b/eslint-local-rules/rules/require-hydration-guard.js
@@ -24,6 +24,8 @@
  *   `withLatestFrom(this.store.select(...))` to get current state
  * - Selectors inside operator callbacks (e.g., inside `switchMap`)
  * - Selectors passed to `withLatestFrom`, `combineLatest`, etc. as secondary sources
+ * - Effects with `{ dispatch: false }` option - they only perform side effects (audio, UI)
+ *   and never dispatch actions that could create duplicate operations during sync
  *
  * ## Examples
  *
@@ -352,6 +354,32 @@ module.exports = {
       return results;
     };
 
+    /**
+     * Check if the createEffect options object has dispatch: false
+     */
+    const hasDispatchFalse = (node) => {
+      // node is a CallExpression for createEffect()
+      // Second argument is the options object: createEffect(() => ..., { dispatch: false })
+      if (node.arguments.length < 2) return false;
+
+      const options = node.arguments[1];
+      if (!options || options.type !== 'ObjectExpression') return false;
+
+      for (const prop of options.properties) {
+        if (
+          prop.type === 'Property' &&
+          prop.key.type === 'Identifier' &&
+          prop.key.name === 'dispatch' &&
+          prop.value.type === 'Literal' &&
+          prop.value.value === false
+        ) {
+          return true;
+        }
+      }
+
+      return false;
+    };
+
     /**
      * Check if a createEffect call contains unguarded selector usage
      */
@@ -359,6 +387,9 @@ module.exports = {
       // node is a CallExpression for createEffect()
       if (node.arguments.length === 0) return;
 
+      // Skip effects with { dispatch: false } - they don't dispatch actions during sync
+      if (hasDispatchFalse(node)) return;
+
       const effectFn = node.arguments[0];
       if (!effectFn) return;
 
diff --git a/src/app/features/focus-mode/store/focus-mode.effects.ts b/src/app/features/focus-mode/store/focus-mode.effects.ts
index 1ba0ba0f5..118e4731a 100644
--- a/src/app/features/focus-mode/store/focus-mode.effects.ts
+++ b/src/app/features/focus-mode/store/focus-mode.effects.ts
@@ -61,6 +61,7 @@ export class FocusModeEffects {
       this.store.select(selectFocusModeConfig),
       this.store.select(selectIsFocusModeEnabled),
     ]).pipe(
+      skipWhileApplyingRemoteOps(),
       switchMap(([cfg, isFocusModeEnabled]) =>
         isFocusModeEnabled && cfg?.isSyncSessionWithTracking && !cfg?.isStartInBackground
           ? this.taskService.currentTaskId$.pipe(
diff --git a/src/app/features/idle/store/idle.effects.ts b/src/app/features/idle/store/idle.effects.ts
index e3b12fc98..010169916 100644
--- a/src/app/features/idle/store/idle.effects.ts
+++ b/src/app/features/idle/store/idle.effects.ts
@@ -107,6 +107,7 @@ export class IdleEffects {
   // while the dialog is open, preventing the flickering between two different values.
   triggerIdleWhenEnabled$ = createEffect(() =>
     this._store.select(selectIdleConfig).pipe(
+      skipWhileApplyingRemoteOps(),
       switchMap(
         ({
           isEnableIdleTimeTracking,
diff --git a/src/app/op-log/testing/integration/lww-update-store-application.integration.spec.ts b/src/app/op-log/testing/integration/lww-update-store-application.integration.spec.ts
index 0122fab6a..647a92e61 100644
--- a/src/app/op-log/testing/integration/lww-update-store-application.integration.spec.ts
+++ b/src/app/op-log/testing/integration/lww-update-store-application.integration.spec.ts
@@ -513,6 +513,7 @@ describe('LWW Update Store Application Integration', () => {
         type: '[UNKNOWN_TYPE] LWW Update',
         id: 'unknown1',
         title: 'Unknown',
+        // eslint-disable-next-line local-rules/require-entity-registry -- intentionally testing unknown entity type handling
         meta: { isPersistent: true, entityType: 'UNKNOWN_TYPE', entityId: 'unknown1' },
       };
 
diff --git a/src/app/root-store/meta/task-shared-meta-reducers/lww-update.meta-reducer.spec.ts b/src/app/root-store/meta/task-shared-meta-reducers/lww-update.meta-reducer.spec.ts
index 67789443b..33d62fe11 100644
--- a/src/app/root-store/meta/task-shared-meta-reducers/lww-update.meta-reducer.spec.ts
+++ b/src/app/root-store/meta/task-shared-meta-reducers/lww-update.meta-reducer.spec.ts
@@ -307,6 +307,7 @@ describe('lwwUpdateMetaReducer', () => {
         type: '[UNKNOWN_ENTITY] LWW Update',
         id: 'unknown-1',
         title: 'Updated Title',
+        // eslint-disable-next-line local-rules/require-entity-registry -- intentionally testing unknown entity type handling
         meta: { isPersistent: true, entityType: 'UNKNOWN_ENTITY', entityId: 'unknown-1' },
       };