feat: add MemoryInfoTool (Item 3)

Creates a new memory_info agent tool that exposes heap used/total, RSS,
CPU core count, and device memory. Uses process.memoryUsage() (available
in Electron renderer) and navigator APIs. Registers as CODING_TOOLS export.
Returns formatted markdown table + detailed breakdown when --detailed flag
is passed.

isReadOnly: true, concurrency-safe, requires READ_ONLY capability.

Author: patil-shubham-dev

apps/desktop/src/renderer/runtime/tools/implementations/MemoryInfoTool.ts

@@ -0,0 +1,86 @@
+import { buildTool, type AgentTool } from '../core/AgentTool'
+import type { ToolContext } from '../core/ToolContext'
+import type { ToolResult } from '../core/ToolResult'
+import { ToolCapabilities } from '../core/ToolCapabilities'
+
+function formatBytes(bytes: number): string {
+  if (bytes < 1024) return `${bytes} B`
+  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`
+  if (bytes < 1024 * 1024 * 1024) return `${(bytes / (1024 * 1024)).toFixed(1)} MB`
+  return `${(bytes / (1024 * 1024 * 1024)).toFixed(2)} GB`
+}
+
+export const MemoryInfoTool: AgentTool = buildTool({
+  name: 'memory_info',
+  aliases: ['meminfo', 'system_info'],
+  description: 'Display current memory usage, CPU information, and system resource utilization. Provides heap usage, total memory, CPU core count, and device memory. Useful for diagnosing performance issues or checking resource availability.',
+  inputSchema: {
+    type: 'object',
+    properties: {
+      detailed: {
+        type: 'boolean',
+        description: 'If true, returns detailed memory breakdown including heap stats',
+      },
+    },
+    required: [],
+  },
+  promptCategory: 'utilities',
+  promptPriority: 55,
+  isReadOnly: () => true,
+  isConcurrencySafe: () => true,
+  requiredCapabilities: () => [ToolCapabilities.READ_ONLY],
+  getActivityDescription: () => 'Checking system memory',
+  execute: async (_ctx: ToolContext, input: Record<string, unknown>): Promise<ToolResult> => {
+    const detailed = input.detailed === true
+    let heapUsed = 0
+    let heapTotal = 0
+    let rss = 0
+
+    try {
+      const mem = process.memoryUsage()
+      heapUsed = mem.heapUsed
+      heapTotal = mem.heapTotal
+      rss = mem.rss
+    } catch {
+      // process.memoryUsage may not be available in all environments
+    }
+
+    const cpuCores = navigator.hardwareConcurrency || 0
+    const deviceMem = (navigator as unknown as { deviceMemory?: number }).deviceMemory || 0
+
+    const summary: Record<string, string> = {
+      'Heap Used': formatBytes(heapUsed),
+      'Heap Total': formatBytes(heapTotal),
+      'RSS': formatBytes(rss),
+      'Heap Usage': heapTotal > 0 ? `${((heapUsed / heapTotal) * 100).toFixed(1)}%` : 'N/A',
+      'CPU Cores': String(cpuCores),
+      'Device Memory': deviceMem > 0 ? `${deviceMem} GB` : 'N/A',
+    }
+
+    let text = '## System Memory Info\n\n'
+    text += '| Metric | Value |\n|---|---|\n'
+    for (const [key, val] of Object.entries(summary)) {
+      text += `| ${key} | ${val} |\n`
+    }
+
+    if (detailed) {
+      const heapDiff = heapTotal - heapUsed
+      text += `\n### Details\n`
+      text += `- Heap fragmentation: ${formatBytes(heapDiff)} free (${heapTotal > 0 ? ((heapDiff / heapTotal) * 100).toFixed(1) : 'N/A'}% of total)\n`
+      text += `- Available device memory: ${deviceMem > 0 ? `${deviceMem} GB` : 'unknown'}\n`
+      text += `- Logical CPU cores: ${cpuCores}\n`
+    }
+
+    return {
+      data: {
+        heapUsed,
+        heapTotal,
+        rss,
+        cpuCores,
+        deviceMemoryGB: deviceMem,
+      },
+      meta: { type: 'memory_info' },
+      newMessages: [{ role: 'user', content: text }],
+    }
+  },
+})

apps/desktop/src/renderer/runtime/tools/implementations/index.ts

@@ -30,6 +30,7 @@ import {
 } from './github/github-tools'
 import { GithubReviewPullRequestTool } from './github/GithubReviewPullRequestTool'
 import { BatchParallelTaskTool } from './batch/BatchParallelTaskTool'
+import { MemoryInfoTool } from './MemoryInfoTool'
 
 export const CODING_TOOLS = [
   ReadFileTool,
@@ -62,6 +63,7 @@ export const CODING_TOOLS = [
   GithubSearchRepoTool,
   GithubReviewPullRequestTool,
   BatchParallelTaskTool,
+  MemoryInfoTool,
 ]
 
 export {
@@ -95,4 +97,5 @@ export {
   GithubSearchRepoTool,
   GithubReviewPullRequestTool,
   BatchParallelTaskTool,
+  MemoryInfoTool,
 }