Fix review findings: toggle logic, preset saving, version lookup, async audio ops

- Fix inverted effects toggle in FloatingGenerateBox
- Add Save button + API method for editing custom effect presets
- Return early on effects save failure in ProfileForm
- Fix no-op ternary in effectsStore
- Handle duplicate preset names with proper 400 response
- Use effects_chain is None instead of label for clean version lookup
- Move blocking audio ops to asyncio.to_thread in async endpoints
- Log warnings instead of silently swallowing parse errors

app/src/lib/api/client.ts

@@ -606,6 +606,16 @@ class ApiClient {
     });
   }
 
+  async updateEffectPreset(
+    presetId: string,
+    data: { name?: string; description?: string; effects_chain?: EffectConfig[] },
+  ): Promise<EffectPresetResponse> {
+    return this.request<EffectPresetResponse>(`/effects/presets/${presetId}`, {
+      method: 'PUT',
+      body: JSON.stringify(data),
+    });
+  }
+
   async deleteEffectPreset(presetId: string): Promise<void> {
     await this.request<void>(`/effects/presets/${presetId}`, {
       method: 'DELETE',

app/src/lib/api/types.ts

@@ -296,6 +296,12 @@ export interface EffectPresetCreate {
   effects_chain: EffectConfig[];
 }
 
+export interface EffectPresetUpdate {
+  name?: string;
+  description?: string;
+  effects_chain?: EffectConfig[];
+}
+
 export interface AvailableEffectParam {
   default: number;
   min: number;