feat(websearch): add managed mcp runtime and provider cooldowns

- switch ccs-websearch MCP to stdio-first framing and keep legacy compatibility

- add cooldown persistence and bounded retries for provider failures

- surface cooldown status in readiness output and regression tests

lib/mcp/ccs-websearch-server.cjs

@@ -61,9 +61,7 @@ function getTools() {
 }
 
 function writeMessage(message) {
-  const body = Buffer.from(JSON.stringify(message), 'utf8');
-  process.stdout.write(`Content-Length: ${body.length}\r\n\r\n`);
-  process.stdout.write(body);
+  process.stdout.write(`${JSON.stringify(message)}\n`);
 }
 
 function writeResponse(id, result) {
@@ -262,26 +260,46 @@ function writeSessionSummary(exitCodeOrSignal) {
 
 function parseMessages() {
   while (true) {
-    const headerEnd = inputBuffer.indexOf('\r\n\r\n');
-    if (headerEnd === -1) {
-      return;
-    }
+    let body;
+    const startsWithLegacyHeaders = inputBuffer
+      .slice(0, Math.min(inputBuffer.length, 32))
+      .toString('utf8')
+      .toLowerCase()
+      .startsWith('content-length:');
 
-    const headerText = inputBuffer.slice(0, headerEnd).toString('utf8');
-    const contentLengthMatch = headerText.match(/content-length:\s*(\d+)/i);
-    if (!contentLengthMatch) {
-      inputBuffer = Buffer.alloc(0);
-      return;
-    }
+    if (startsWithLegacyHeaders) {
+      const headerEnd = inputBuffer.indexOf('\r\n\r\n');
+      if (headerEnd === -1) {
+        return;
+      }
 
-    const contentLength = Number.parseInt(contentLengthMatch[1], 10);
-    const messageEnd = headerEnd + 4 + contentLength;
-    if (inputBuffer.length < messageEnd) {
-      return;
-    }
+      const headerText = inputBuffer.slice(0, headerEnd).toString('utf8');
+      const contentLengthMatch = headerText.match(/content-length:\s*(\d+)/i);
+      if (!contentLengthMatch) {
+        inputBuffer = Buffer.alloc(0);
+        return;
+      }
 
-    const body = inputBuffer.slice(headerEnd + 4, messageEnd).toString('utf8');
-    inputBuffer = inputBuffer.slice(messageEnd);
+      const contentLength = Number.parseInt(contentLengthMatch[1], 10);
+      const messageEnd = headerEnd + 4 + contentLength;
+      if (inputBuffer.length < messageEnd) {
+        return;
+      }
+
+      body = inputBuffer.slice(headerEnd + 4, messageEnd).toString('utf8');
+      inputBuffer = inputBuffer.slice(messageEnd);
+    } else {
+      const newlineIndex = inputBuffer.indexOf('\n');
+      if (newlineIndex === -1) {
+        return;
+      }
+
+      body = inputBuffer.slice(0, newlineIndex).toString('utf8').replace(/\r$/, '').trim();
+      inputBuffer = inputBuffer.slice(newlineIndex + 1);
+      if (!body) {
+        continue;
+      }
+    }
 
     let message;
     try {