feat(ruview): secure community metaharness flywheel (#1467)

* feat(ruview): add secure community metaharness flywheel

* fix(ruview): canonicalize manifest line endings

harness/ruview/src/mcp-server.js

@@ -17,6 +17,8 @@ import { readFileSync } from 'node:fs';
 import { listTools, runTool } from './tools.js';
 
 const PROTOCOL_VERSION = '2024-11-05';
+const MAX_REQUEST_BYTES = 256 * 1024;
+const MAX_QUEUED_TOOL_CALLS = 20;
 // Single-source the version from package.json (ADR-263 O6).
 const PKG = JSON.parse(readFileSync(new URL('../package.json', import.meta.url), 'utf8'));
 const SERVER_INFO = { name: 'ruview', version: PKG.version };
@@ -28,7 +30,7 @@ function result(id, res) { send({ jsonrpc: '2.0', id, result: res }); }
 function error(id, code, message) { send({ jsonrpc: '2.0', id, error: { code, message } }); }
 function log(...a) { process.stderr.write('[ruview-mcp] ' + a.join(' ') + '\n'); }
 
-async function handle(msg) {
+async function handle(msg, context = {}) {
   const { id, method, params } = msg;
   switch (method) {
     case 'initialize':
@@ -40,8 +42,10 @@ async function handle(msg) {
       });
     case 'notifications/initialized':
     case 'initialized':
-    case 'notifications/cancelled':
       return; // notifications — no response
+    case 'notifications/cancelled':
+      if (context.queuedIds?.has(params?.requestId)) context.cancelled?.add(params.requestId);
+      return; // queued requests are cancelled before execution
     case 'ping':
       return result(id, {});
     case 'tools/list':
@@ -53,7 +57,8 @@ async function handle(msg) {
     case 'tools/call': {
       const name = params?.name;
       const args = params?.arguments || {};
-      const out = await runTool(name, args);
+      log('audit', JSON.stringify({ event: 'tools/call', id, name }));
+      const out = await runTool(name, args, context);
       // MCP content envelope: text block with the JSON, isError reflects ok=false.
       return result(id, {
         content: [{ type: 'text', text: JSON.stringify(out, null, 2) }],
@@ -75,19 +80,55 @@ export function startMcpServer() {
   // answer during a long tool run). `toolChain` also lets stdin-close drain the
   // in-flight call so its response is flushed instead of dropped by process.exit.
   let toolChain = Promise.resolve();
+  let queuedToolCalls = 0;
+  const cancelled = new Set();
+  const queuedIds = new Set();
 
-  const dispatch = (msg) => handle(msg).catch((err) => {
+  const grants = String(process.env.RUVIEW_MCP_GRANTS || '').split(',').map((v) => v.trim()).filter(Boolean);
+  const dispatch = (msg) => handle(msg, { source: 'mcp', grants, cancelled, queuedIds }).catch((err) => {
     if (msg && msg.id !== undefined) error(msg.id, -32603, String(err && err.message || err));
     log('handler error:', String(err));
   });
 
   rl.on('line', (line) => {
+    if (Buffer.byteLength(line, 'utf8') > MAX_REQUEST_BYTES) {
+      log('oversized JSON-RPC line dropped');
+      return;
+    }
     const s = line.trim();
     if (!s) return;
     let msg;
     try { msg = JSON.parse(s); } catch { return log('bad JSON line dropped'); }
     if (msg && msg.method === 'tools/call') {
-      toolChain = toolChain.then(() => dispatch(msg)); // one tool at a time
+      const validId = typeof msg.id === 'string' || (typeof msg.id === 'number' && Number.isFinite(msg.id));
+      if (!validId) {
+        error(msg?.id ?? null, -32600, 'tools/call requires a finite string or number id');
+        return;
+      }
+      if (queuedIds.has(msg.id)) {
+        error(msg.id, -32600, 'Duplicate in-flight request id');
+        return;
+      }
+      if (queuedToolCalls >= MAX_QUEUED_TOOL_CALLS) {
+        if (msg.id !== undefined) error(msg.id, -32000, 'Tool queue is full');
+        log('tool queue full:', String(msg.id));
+        return;
+      }
+      queuedToolCalls += 1;
+      queuedIds.add(msg.id);
+      toolChain = toolChain.then(async () => {
+        try {
+          if (cancelled.delete(msg.id)) {
+            if (msg.id !== undefined) error(msg.id, -32800, 'Request cancelled');
+            return;
+          }
+          await dispatch(msg);
+        } finally {
+          cancelled.delete(msg.id);
+          queuedIds.delete(msg.id);
+          queuedToolCalls -= 1;
+        }
+      }); // one tool at a time
     } else {
       dispatch(msg); // health/list/handshake answer immediately, even mid tool run
     }