feat: implement browser extension UI with WebAssembly integration

extension/dist/background/index.js

@@ -0,0 +1,81 @@
+// Background service worker for Modular Vault Extension
+// Handles state persistence between popup sessions
+
+console.log('Background service worker started');
+
+// Store session state locally for quicker access
+let sessionState = {
+  currentKeyspace: null,
+  keypairs: [],
+  selectedKeypair: null
+};
+
+// Initialize state from storage
+chrome.storage.local.get(['currentKeyspace', 'keypairs', 'selectedKeypair'])
+  .then(state => {
+    sessionState = {
+      currentKeyspace: state.currentKeyspace || null,
+      keypairs: state.keypairs || [],
+      selectedKeypair: state.selectedKeypair || null
+    };
+    console.log('Session state loaded from storage:', sessionState);
+  })
+  .catch(error => {
+    console.error('Failed to load session state:', error);
+  });
+
+// Handle messages from the popup
+chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
+  console.log('Background received message:', message.action, message.type || '');
+  
+  // Update session state
+  if (message.action === 'update_session') {
+    try {
+      const { type, data } = message;
+      
+      // Update our local state
+      if (type === 'keyspace') {
+        sessionState.currentKeyspace = data;
+      } else if (type === 'keypair_selected') {
+        sessionState.selectedKeypair = data;
+      } else if (type === 'keypair_added') {
+        sessionState.keypairs = [...sessionState.keypairs, data];
+      } else if (type === 'keypairs_loaded') {
+        // Replace the entire keypair list with what came from the vault
+        console.log('Updating keypairs from vault:', data);
+        sessionState.keypairs = data;
+      } else if (type === 'session_locked') {
+        // When locking, we don't need to maintain keypairs in memory anymore
+        // since they'll be reloaded from the vault when unlocking
+        sessionState = {
+          currentKeyspace: null,
+          keypairs: [], // Clear keypairs from memory since they're in the vault
+          selectedKeypair: null
+        };
+      }
+      
+      // Persist to storage
+      chrome.storage.local.set(sessionState)
+        .then(() => {
+          console.log('Updated session state in storage:', sessionState);
+          sendResponse({ success: true });
+        })
+        .catch(error => {
+          console.error('Failed to persist session state:', error);
+          sendResponse({ success: false, error: error.message });
+        });
+      
+      return true; // Keep connection open for async response
+    } catch (error) {
+      console.error('Error in update_session message handler:', error);
+      sendResponse({ success: false, error: error.message });
+      return true;
+    }
+  }
+  
+  // Get session state
+  if (message.action === 'get_session') {
+    sendResponse(sessionState);
+    return false; // No async response needed
+  }
+});