Add comprehensive tests for vector/semantic search functionality

- Implement full coverage tests for Embedder model loading and embedding generation
- Add CRUD operations and caching tests for VectorStore
- Include cosine similarity computation tests
- Validate semantic search accuracy and relevance through various queries
- Establish performance benchmarks for embedding and search operations
- Ensure edge cases and error handling are covered
- Test thread safety and concurrent access scenarios
- Verify availability of semantic search dependencies

ccw/src/core/websocket.ts

@@ -0,0 +1,190 @@
+// @ts-nocheck
+import { createHash } from 'crypto';
+
+// WebSocket clients for real-time notifications
+export const wsClients = new Set();
+
+export function handleWebSocketUpgrade(req, socket, head) {
+  const key = req.headers['sec-websocket-key'];
+  const acceptKey = createHash('sha1')
+    .update(key + '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')
+    .digest('base64');
+
+  const responseHeaders = [
+    'HTTP/1.1 101 Switching Protocols',
+    'Upgrade: websocket',
+    'Connection: Upgrade',
+    `Sec-WebSocket-Accept: ${acceptKey}`,
+    '',
+    ''
+  ].join('\r\n');
+
+  socket.write(responseHeaders);
+
+  // Add to clients set
+  wsClients.add(socket);
+  console.log(`[WS] Client connected (${wsClients.size} total)`);
+
+  // Handle incoming messages
+  socket.on('data', (buffer) => {
+    try {
+      const frame = parseWebSocketFrame(buffer);
+      if (!frame) return;
+
+      const { opcode, payload } = frame;
+
+      switch (opcode) {
+        case 0x1: // Text frame
+          if (payload) {
+            console.log('[WS] Received:', payload);
+          }
+          break;
+        case 0x8: // Close frame
+          socket.end();
+          break;
+        case 0x9: // Ping frame - respond with Pong
+          const pongFrame = Buffer.alloc(2);
+          pongFrame[0] = 0x8A; // Pong opcode with FIN bit
+          pongFrame[1] = 0x00; // No payload
+          socket.write(pongFrame);
+          break;
+        case 0xA: // Pong frame - ignore
+          break;
+        default:
+          // Ignore other frame types (binary, continuation)
+          break;
+      }
+    } catch (e) {
+      // Ignore parse errors
+    }
+  });
+
+  // Handle disconnect
+  socket.on('close', () => {
+    wsClients.delete(socket);
+    console.log(`[WS] Client disconnected (${wsClients.size} remaining)`);
+  });
+
+  socket.on('error', () => {
+    wsClients.delete(socket);
+  });
+}
+
+/**
+ * Parse WebSocket frame (simplified)
+ * Returns { opcode, payload } or null
+ */
+export function parseWebSocketFrame(buffer) {
+  if (buffer.length < 2) return null;
+
+  const firstByte = buffer[0];
+  const opcode = firstByte & 0x0f; // Extract opcode (bits 0-3)
+
+  // Opcode types:
+  // 0x0 = continuation, 0x1 = text, 0x2 = binary
+  // 0x8 = close, 0x9 = ping, 0xA = pong
+
+  const secondByte = buffer[1];
+  const isMasked = (secondByte & 0x80) !== 0;
+  let payloadLength = secondByte & 0x7f;
+
+  let offset = 2;
+  if (payloadLength === 126) {
+    payloadLength = buffer.readUInt16BE(2);
+    offset = 4;
+  } else if (payloadLength === 127) {
+    payloadLength = Number(buffer.readBigUInt64BE(2));
+    offset = 10;
+  }
+
+  let mask = null;
+  if (isMasked) {
+    mask = buffer.slice(offset, offset + 4);
+    offset += 4;
+  }
+
+  const payload = buffer.slice(offset, offset + payloadLength);
+
+  if (isMasked && mask) {
+    for (let i = 0; i < payload.length; i++) {
+      payload[i] ^= mask[i % 4];
+    }
+  }
+
+  return { opcode, payload: payload.toString('utf8') };
+}
+
+/**
+ * Create WebSocket frame
+ */
+export function createWebSocketFrame(data) {
+  const payload = Buffer.from(JSON.stringify(data), 'utf8');
+  const length = payload.length;
+
+  let frame;
+  if (length <= 125) {
+    frame = Buffer.alloc(2 + length);
+    frame[0] = 0x81; // Text frame, FIN
+    frame[1] = length;
+    payload.copy(frame, 2);
+  } else if (length <= 65535) {
+    frame = Buffer.alloc(4 + length);
+    frame[0] = 0x81;
+    frame[1] = 126;
+    frame.writeUInt16BE(length, 2);
+    payload.copy(frame, 4);
+  } else {
+    frame = Buffer.alloc(10 + length);
+    frame[0] = 0x81;
+    frame[1] = 127;
+    frame.writeBigUInt64BE(BigInt(length), 2);
+    payload.copy(frame, 10);
+  }
+
+  return frame;
+}
+
+/**
+ * Broadcast message to all connected WebSocket clients
+ */
+export function broadcastToClients(data) {
+  const frame = createWebSocketFrame(data);
+
+  for (const client of wsClients) {
+    try {
+      client.write(frame);
+    } catch (e) {
+      wsClients.delete(client);
+    }
+  }
+
+  console.log(`[WS] Broadcast to ${wsClients.size} clients:`, data.type);
+}
+
+/**
+ * Extract session ID from file path
+ */
+export function extractSessionIdFromPath(filePath) {
+  // Normalize path
+  const normalized = filePath.replace(/\\/g, '/');
+
+  // Look for session pattern: WFS-xxx, WRS-xxx, etc.
+  const sessionMatch = normalized.match(/\/(W[A-Z]S-[^/]+)\//);
+  if (sessionMatch) {
+    return sessionMatch[1];
+  }
+
+  // Look for .workflow/.sessions/xxx pattern
+  const sessionsMatch = normalized.match(/\.workflow\/\.sessions\/([^/]+)/);
+  if (sessionsMatch) {
+    return sessionsMatch[1];
+  }
+
+  // Look for lite-plan/lite-fix pattern
+  const liteMatch = normalized.match(/\.(lite-plan|lite-fix)\/([^/]+)/);
+  if (liteMatch) {
+    return liteMatch[2];
+  }
+
+  return null;
+}