feat: Add apply_diff tool for efficient file editing

.claude/settings.local.json

@@ -2,7 +2,8 @@
   "permissions": {
     "allow": [
       "WebSearch",
-      "WebFetch(domain:ai-sdk.dev)"
+      "WebFetch(domain:ai-sdk.dev)",
+      "Bash(cat:*)"
     ],
     "deny": [],
     "ask": []

biome.json

@@ -0,0 +1,28 @@
+{
+  "$schema": "https://biomejs.dev/schemas/2.3.4/schema.json",
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true
+    }
+  },
+  "formatter": {
+    "enabled": true,
+    "formatWithErrors": false,
+    "indentStyle": "space",
+    "indentWidth": 2,
+    "lineWidth": 100,
+    "lineEnding": "lf"
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "single",
+      "trailingCommas": "all",
+      "semicolons": "always"
+    }
+  },
+  "files": {
+    "ignoreUnknown": false,
+    "includes": ["**/*.js", "**/*.jsx", "**/*.ts", "**/*.tsx", "**/*.json", "**/*.jsonc"]
+  }
+}

bundle.ts

@@ -0,0 +1,15 @@
+#!/usr/bin/env bun
+
+import { $ } from "bun";
+import { version } from "./package.json";
+
+// Build binary for current platform (chai-cli)
+console.log(`→ Building chai-cli v${version} binary...`);
+
+try {
+  await $`bun build ./index.ts --compile --outfile=./dist/chai-cli-v${version}`;
+  console.log(`✓ Binary created at ./dist/chai-cli-v${version}`);
+} catch (error) {
+  console.error("✗ Build failed:", error);
+  process.exit(1);
+}