fix: encrypted data breaks Firefox — injector can't decrypt — v2.0.13

When at-rest encryption is enabled, storage.local contains encrypted
blobs. The injector reads raw storage (content script world, no
access to IndexedDB CryptoKey) and sees { _ssLocalEncrypted: true }.
It passed empty config to content.js → no mappings → no substitution.

This is why Firefox stopped working after encryption was enabled.
Chrome/Brave worked because the user hadn't set up encryption there.

Fixed: injector now detects encrypted data and asks the background
script for decrypted config via 'get:decrypted-config' message.
The background uses the Storage module (which has IndexedDB access)
to decrypt and return the data. Falls back to empty config if the
vault is actually locked.

https://claude.ai/code/session_01SWSwDfMVij53bCTNSCLMwn

src/background/service-worker.js

@@ -163,6 +163,17 @@ const messageHandlers = {
     await setupAutoSyncAlarm();
   },
 
+  async 'get:decrypted-config'(_message, _sender, sendResponse) {
+    try {
+      const mappings = await Storage.getMappings();
+      const identity = await Storage.getIdentity();
+      const settings = await Storage.getSettings();
+      sendResponse({ mappings, identity, settings });
+    } catch {
+      sendResponse(null);
+    }
+  },
+
   async 'org:config-changed'() {
     await setupOrgPolicyAlarm();
   },