feat: add tool framework foundation (types, registry, executor, shell tool, model types, SOUL.md)

- Task 0: SOUL.md + loadSystemPrompt() in daemon
- Task 1: Tool type definitions (Tool, ToolCall, ToolResult, etc.)
- Task 2: ToolRegistry with Anthropic/OpenAI serialization
- Task 3: ToolExecutor with hooks, timeout, truncation
- Task 4: shell.exec builtin tool
- Task 8: Model types updated for tool use (ToolDefinition, ModelToolCall, etc.)
- Task 15: Model index exports for tool types

src/tools/registry.test.ts

@@ -0,0 +1,79 @@
+import { describe, it, expect } from 'vitest';
+import { ToolRegistry } from './registry.js';
+import type { Tool } from './types.js';
+
+const echoTool: Tool = {
+  name: 'test.echo',
+  description: 'Echoes input back',
+  inputSchema: {
+    type: 'object',
+    properties: { text: { type: 'string', description: 'Text to echo' } },
+    required: ['text'],
+  },
+  execute: async (args) => ({ success: true, output: String((args as { text: string }).text) }),
+};
+
+const greetTool: Tool = {
+  name: 'test.greet',
+  description: 'Greets someone',
+  inputSchema: {
+    type: 'object',
+    properties: { name: { type: 'string' } },
+    required: ['name'],
+  },
+  execute: async (args) => ({ success: true, output: `Hello ${(args as { name: string }).name}` }),
+};
+
+describe('ToolRegistry', () => {
+  it('registers and retrieves tools by name', () => {
+    const registry = new ToolRegistry();
+    registry.register(echoTool);
+
+    expect(registry.get('test.echo')).toBe(echoTool);
+    expect(registry.get('nonexistent')).toBeUndefined();
+  });
+
+  it('lists all registered tools', () => {
+    const registry = new ToolRegistry();
+    registry.register(echoTool);
+    registry.register(greetTool);
+
+    const tools = registry.list();
+    expect(tools).toHaveLength(2);
+    expect(tools.map(t => t.name)).toContain('test.echo');
+    expect(tools.map(t => t.name)).toContain('test.greet');
+  });
+
+  it('throws on duplicate registration', () => {
+    const registry = new ToolRegistry();
+    registry.register(echoTool);
+    expect(() => registry.register(echoTool)).toThrow('already registered');
+  });
+
+  it('serializes to Anthropic format', () => {
+    const registry = new ToolRegistry();
+    registry.register(echoTool);
+
+    const anthropicTools = registry.toAnthropicFormat();
+    expect(anthropicTools).toEqual([{
+      name: 'test.echo',
+      description: 'Echoes input back',
+      input_schema: echoTool.inputSchema,
+    }]);
+  });
+
+  it('serializes to OpenAI format', () => {
+    const registry = new ToolRegistry();
+    registry.register(echoTool);
+
+    const openaiTools = registry.toOpenAIFormat();
+    expect(openaiTools).toEqual([{
+      type: 'function',
+      function: {
+        name: 'test.echo',
+        description: 'Echoes input back',
+        parameters: echoTool.inputSchema,
+      },
+    }]);
+  });
+});