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.ts

@@ -0,0 +1,54 @@
+import type { Tool, ToolInputSchema } from './types.js';
+
+export interface AnthropicToolDef {
+  name: string;
+  description: string;
+  input_schema: ToolInputSchema;
+}
+
+export interface OpenAIToolDef {
+  type: 'function';
+  function: {
+    name: string;
+    description: string;
+    parameters: ToolInputSchema;
+  };
+}
+
+export class ToolRegistry {
+  private tools: Map<string, Tool> = new Map();
+
+  register(tool: Tool): void {
+    if (this.tools.has(tool.name)) {
+      throw new Error(`Tool '${tool.name}' is already registered`);
+    }
+    this.tools.set(tool.name, tool);
+  }
+
+  get(name: string): Tool | undefined {
+    return this.tools.get(name);
+  }
+
+  list(): Tool[] {
+    return Array.from(this.tools.values());
+  }
+
+  toAnthropicFormat(): AnthropicToolDef[] {
+    return this.list().map(t => ({
+      name: t.name,
+      description: t.description,
+      input_schema: t.inputSchema,
+    }));
+  }
+
+  toOpenAIFormat(): OpenAIToolDef[] {
+    return this.list().map(t => ({
+      type: 'function' as const,
+      function: {
+        name: t.name,
+        description: t.description,
+        parameters: t.inputSchema,
+      },
+    }));
+  }
+}