feat(extension): update devices UI for new auth model

- Show revoked devices in collapsible section with strikethrough styling
- Fetch revoked.json via new list_revoked message + router case
- Registration flow uses register_device WASM API (private keys internal)
- Display revoked_by and timestamp for each revoked entry
- Update setup wizard to use new register_device API

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

extension/src/setup/setup.ts

@@ -1049,12 +1049,12 @@ function attachStep5(): void {
 
     try {
       const w = await loadWasm();
-      const keypair = w.generate_device_keypair();
+      // register_device keeps private keys internal — only public keys returned
+      const keypair = w.register_device(state.deviceName);
 
-      // 1) Save private key + name locally.
+      // 1) Save device name locally (private keys stay in WASM memory).
       await chrome.storage.local.set({
         device_name: state.deviceName,
-        device_private_key: keypair.private_key_base64,
       });
 
       // 2) Save vault config + reference image to extension storage.
@@ -1086,7 +1086,7 @@ function attachStep5(): void {
       const host = createGitHost(state.hostType, hostUrl, state.repoPath, state.apiToken);
       await addDevice(host, {
         name: state.deviceName,
-        public_key: keypair.public_key_hex,
+        public_key: keypair.signing_public_key,
         added_at: Math.floor(Date.now() / 1000),
       });