refactor(omnium): Simplify CapletController state structure

Consolidate CapletControllerState from multiple top-level keys
(installed, manifests, subclusters, installedAt) into a single
`caplets: Record<CapletId, InstalledCaplet>` structure.

Changes:
- Add ControllerStorage abstraction using Immer for state management
- Controllers work with typed state object instead of storage keys
- Only modified top-level keys are persisted (via Immer patches)
- Remove state corruption checks (no longer possible with atomic storage)
- Fix makeFacet type - use string | symbol instead of keyof MethodGuard
- Update PLAN.md to reflect new storage architecture

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: rekmarks

packages/omnium-gatherum/PLAN.md

@@ -106,7 +106,11 @@ capabilities.
     - `NamespacedStorage`: Scoped storage interface with automatic key prefixing
   - `controllers/storage/chrome-storage.ts`: `makeChromeStorageAdapter()` for Chrome Storage API
   - `controllers/storage/namespaced-storage.ts`: `makeNamespacedStorage()` factory
-  - Storage keys automatically prefixed: `${namespace}.${key}` (e.g., `caplet.com.example.test.manifest`)
+  - `controllers/storage/controller-storage.ts`: `makeControllerStorage()` for controller state management
+    - Controllers work with a typed `state` object instead of managing storage keys directly
+    - Uses Immer for immutable updates with change tracking
+    - Only persists modified top-level keys (via Immer patches)
+    - Storage keys automatically prefixed: `${namespace}.${key}` (e.g., `caplet.caplets`)
 
 - [x] **Caplet Manifest Schema**
 
@@ -126,11 +130,11 @@ capabilities.
     - `list()`: Get all installed caplets
     - `get(capletId)`: Get specific caplet
     - `getByService(serviceName)`: Find caplet providing a service
-  - Storage keys (within `caplet` namespace):
-    - `installed`: Array of installed caplet IDs
-    - `${capletId}.manifest`: CapletManifest JSON
-    - `${capletId}.subclusterId`: Associated subcluster ID
-    - `${capletId}.installedAt`: Installation timestamp
+  - State structure (`CapletControllerState`):
+    - `caplets`: `Record<CapletId, InstalledCaplet>` - all caplet data in a single record
+  - Uses `ControllerStorage<CapletControllerState>` for state management
+    - Synchronous reads via `storage.state.caplets[id]`
+    - Async updates via `storage.update(draft => { ... })`
 
 - [x] **Dev Console Integration**
 

packages/omnium-gatherum/package.json

@@ -53,6 +53,7 @@
     "@metamask/streams": "workspace:^",
     "@metamask/superstruct": "^3.2.1",
     "@metamask/utils": "^11.4.2",
+    "immer": "^10.1.1",
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
     "semver": "^7.7.1",

packages/omnium-gatherum/src/background.ts

@@ -17,10 +17,14 @@ import { ChromeRuntimeDuplexStream } from '@metamask/streams/browser';
 
 import {
   makeChromeStorageAdapter,
-  makeNamespacedStorage,
+  makeControllerStorage,
   makeCapletController,
 } from './controllers/index.ts';
-import type { CapletManifest, LaunchResult } from './controllers/index.ts';
+import type {
+  CapletControllerState,
+  CapletManifest,
+  LaunchResult,
+} from './controllers/index.ts';
 
 defineGlobals();
 
@@ -120,9 +124,16 @@ async function main(): Promise<void> {
     return kernelP;
   };
 
-  // Create storage adapter and namespaced storage for caplets
+  // Create storage adapter and state storage for caplets
   const storageAdapter = makeChromeStorageAdapter();
-  const capletStorage = makeNamespacedStorage('caplet', storageAdapter);
+  const defaultCapletState: CapletControllerState = {
+    caplets: {},
+  };
+  const capletStorage = await makeControllerStorage({
+    namespace: 'caplet',
+    adapter: storageAdapter,
+    defaultState: defaultCapletState,
+  });
 
   // Create CapletController with attenuated kernel access
   const capletController = makeCapletController(