chore: add changeset for v0.5.0 and update documentation

Changeset:
- Add changeset for minor version bump (→ 0.5.0)
- Bumps @lytics/dev-agent-core and @lytics/dev-agent

Scanner docs:
- Update README with new DocumentType 'variable' and metadata fields
- Document isArrowFunction, isHook, isAsync, isConstant, constantKind

Website docs:
- Add 'New in v0.5.0' section to tools index
- Update dev_search with v0.5 markers for new extraction types
- Update quickstart with expanded extraction list

Author: prosdev

.changeset/arrow-function-extraction.md

@@ -0,0 +1,48 @@
+---
+"@lytics/dev-agent-core": minor
+"@lytics/dev-agent": minor
+---
+
+feat(scanner): Extract arrow functions, function expressions, and exported constants
+
+### New Features
+
+**Arrow Function Extraction**
+- Extract arrow functions assigned to `const`/`let` variables
+- Extract function expressions assigned to variables
+- Detect React hooks automatically (`use*` naming pattern)
+- Detect async arrow functions
+
+**Exported Constant Extraction**
+- Extract exported `const` with object literal initializers (config objects)
+- Extract exported `const` with array literal initializers (static lists)
+- Extract exported `const` with call expression initializers (factories like `createContext()`)
+
+### API Changes
+
+**New DocumentType value:**
+- Added `'variable'` to `DocumentType` union
+
+**New metadata fields:**
+- `isArrowFunction?: boolean` - true for arrow functions (vs function expressions)
+- `isHook?: boolean` - true if name matches `/^use[A-Z]/` (React convention)
+- `isAsync?: boolean` - true for async functions
+- `isConstant?: boolean` - true for exported constants
+- `constantKind?: 'object' | 'array' | 'value'` - kind of constant initializer
+
+### Examples
+
+Now extracts:
+```typescript
+export const useAuth = () => { ... }           // Hook (isHook: true)
+export const fetchData = async (url) => { ... } // Async (isAsync: true)
+const validateEmail = (email: string) => ...   // Utility function
+export const API_CONFIG = { baseUrl: '...' }   // Object constant
+export const LANGUAGES = ['ts', 'js']          // Array constant
+export const AppContext = createContext({})    // Factory constant
+```
+
+### Migration
+
+No breaking changes. The new `'variable'` DocumentType is additive. Existing queries for `'function'`, `'class'`, etc. continue to work unchanged.
+

packages/core/src/scanner/README.md

@@ -56,7 +56,7 @@ Represents a single extracted code element or documentation section:
 interface Document {
   id: string;                // Unique identifier: "file:name:line"
   text: string;              // Text to embed (for vector search)
-  type: DocumentType;        // 'function' | 'class' | 'interface' | 'type' | 'method' | 'documentation'
+  type: DocumentType;        // 'function' | 'class' | 'interface' | 'type' | 'method' | 'documentation' | 'variable'
   language: string;          // 'typescript' | 'javascript' | 'markdown'
 
   metadata: {
@@ -67,6 +67,13 @@ interface Document {
     signature?: string;      // Full signature
     exported: boolean;       // Is it a public API?
     docstring?: string;      // Documentation comment
+    
+    // Variable/function metadata (for type: 'variable')
+    isArrowFunction?: boolean;  // True for arrow functions
+    isHook?: boolean;           // True for React hooks (use* pattern)
+    isAsync?: boolean;          // True for async functions
+    isConstant?: boolean;       // True for exported constants
+    constantKind?: 'object' | 'array' | 'value';  // Kind of constant
   };
 }
 ```
@@ -364,8 +371,8 @@ const utilDocs = result.documents.filter(
 
 | Language | Scanner | Extracts | Status |
 |----------|---------|----------|--------|
-| TypeScript | `TypeScriptScanner` | Functions, classes, methods, interfaces, types, JSDoc | ✅ Implemented |
-| JavaScript | `TypeScriptScanner` | Functions, classes, methods, JSDoc | ✅ Implemented (via .ts scanner) |
+| TypeScript | `TypeScriptScanner` | Functions, classes, methods, interfaces, types, arrow functions, exported constants, JSDoc | ✅ Implemented |
+| JavaScript | `TypeScriptScanner` | Functions, classes, methods, arrow functions, exported constants, JSDoc | ✅ Implemented (via .ts scanner) |
 | Markdown | `MarkdownScanner` | Documentation sections, code blocks | ✅ Implemented |
 | Go | - | Functions, structs, interfaces | 🔄 Planned (tree-sitter) |
 | Python | - | Functions, classes, docstrings | 🔄 Planned (tree-sitter) |

website/content/docs/quickstart.mdx

@@ -71,7 +71,7 @@ Try these prompts:
 When you run `dev index .`:
 
 1. **Scanner** parses your code using the TypeScript Compiler API
-2. **Extractor** identifies functions, classes, interfaces, types
+2. **Extractor** identifies functions, classes, interfaces, types, arrow functions, hooks, and exported constants
 3. **Embedder** generates vector embeddings locally (MiniLM-L6-v2)
 4. **Storage** saves everything to LanceDB (`~/.dev-agent/indexes/`)
 

website/content/docs/tools/dev-search.mdx

@@ -86,11 +86,13 @@ This surfaces test files without affecting semantic search rankings — tests ar
 
 dev_search indexes these code components:
 
-- **Functions** — Named functions and arrow functions
+- **Functions** — Named function declarations
+- **Arrow functions** — Arrow functions assigned to variables (e.g., `const handler = () => {}`) ✨ v0.5
+- **React hooks** — Automatically detected by `use*` naming pattern ✨ v0.5
 - **Classes** — Class declarations and their methods
 - **Interfaces** — TypeScript interfaces
 - **Types** — Type aliases
-- **Variables** — Exported constants and variables
+- **Exported constants** — Objects, arrays, and factory calls (e.g., `export const CONFIG = {}`) ✨ v0.5
 - **Markdown sections** — Headers and content blocks
 
 ## Tips

website/content/docs/tools/index.mdx

@@ -16,7 +16,12 @@ dev-agent provides nine tools through the Model Context Protocol (MCP). These to
 | [`dev_status`](/docs/tools/dev-status) | Check repository indexing status |
 | [`dev_health`](/docs/tools/dev-health) | Monitor MCP server health |
 
-## New in v0.4.0
+## New in v0.5.0
+
+- **Enhanced indexing** — Arrow functions, React hooks, and exported constants now extracted
+- **`dev_search`** — Better coverage of modern JavaScript patterns (hooks, utilities, configs)
+
+## v0.4.0
 
 - **`dev_history`** — Semantic search over git commit history
 - **`dev_map`** — Change frequency indicators (🔥 hot, ✏️ active, 📝 recent)