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/executor.ts

@@ -0,0 +1,68 @@
+import type { ToolResult } from './types.js';
+import type { ToolRegistry } from './registry.js';
+import type { HookEngine } from '../hooks/engine.js';
+
+export interface ToolExecutorConfig {
+  defaultTimeoutMs?: number;
+  maxOutputBytes?: number;
+}
+
+export class ToolExecutor {
+  private registry: ToolRegistry;
+  private hooks: HookEngine;
+  private defaultTimeoutMs: number;
+  private maxOutputBytes: number;
+
+  constructor(registry: ToolRegistry, hooks: HookEngine, config?: ToolExecutorConfig) {
+    this.registry = registry;
+    this.hooks = hooks;
+    this.defaultTimeoutMs = config?.defaultTimeoutMs ?? 30_000;
+    this.maxOutputBytes = config?.maxOutputBytes ?? 51_200;
+  }
+
+  async execute(toolName: string, args: unknown): Promise<ToolResult> {
+    const tool = this.registry.get(toolName);
+    if (!tool) {
+      return { success: false, output: '', error: `Tool '${toolName}' not found` };
+    }
+
+    // Check hooks
+    const action = this.hooks.getAction(toolName);
+    if (action === 'confirm') {
+      const hookResult = await this.hooks.requestConfirmation(
+        toolName,
+        args as Record<string, unknown>,
+      );
+      if (!hookResult.approved) {
+        return {
+          success: false,
+          output: '',
+          error: `Tool '${toolName}' denied by user: ${hookResult.reason ?? 'no reason'}`,
+        };
+      }
+    }
+
+    // Execute with timeout
+    try {
+      const result = await Promise.race([
+        tool.execute(args),
+        new Promise<ToolResult>((_, reject) =>
+          setTimeout(() => reject(new Error(`Tool '${toolName}' timed out after ${this.defaultTimeoutMs}ms`)), this.defaultTimeoutMs)
+        ),
+      ]);
+
+      // Truncate output if too large
+      if (result.output.length > this.maxOutputBytes) {
+        result.output = result.output.slice(0, this.maxOutputBytes) + '\n[truncated]';
+      }
+
+      return result;
+    } catch (error) {
+      return {
+        success: false,
+        output: '',
+        error: error instanceof Error ? error.message : String(error),
+      };
+    }
+  }
+}