feat(config): add config read/write and defaults

src/core/config.ts

@@ -0,0 +1,33 @@
+import { existsSync, readFileSync, writeFileSync, mkdirSync } from 'fs';
+import { dirname } from 'path';
+import { getConfigPath } from './paths.js';
+import { ConfigSchema, type Config } from './schema.js';
+
+export function defaultConfig(projectName: string): Config {
+  return {
+    version: '1',
+    projectName,
+    delegationMode: 'suggest',
+    roles: {
+      architect: { preferredAgent: 'claude' },
+      implementer: { preferredAgent: 'codex' },
+      reviewer: { preferredAgent: 'claude' },
+      tester: { preferredAgent: 'codex' },
+    },
+  };
+}
+
+export function loadConfig(cwd: string): Config {
+  const path = getConfigPath(cwd);
+  if (!existsSync(path)) {
+    throw new Error('AgentHub not initialized. Run: agenthub init');
+  }
+  const raw = JSON.parse(readFileSync(path, 'utf-8'));
+  return ConfigSchema.parse(raw);
+}
+
+export function saveConfig(cwd: string, config: Config): void {
+  const path = getConfigPath(cwd);
+  mkdirSync(dirname(path), { recursive: true });
+  writeFileSync(path, JSON.stringify(config, null, 2), 'utf-8');
+}

tests/config.test.ts

@@ -0,0 +1,25 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdtempSync, rmSync } from 'fs';
+import { tmpdir } from 'os';
+import { join } from 'path';
+import { loadConfig, saveConfig, defaultConfig } from '../src/core/config.js';
+
+describe('config', () => {
+  let cwd: string;
+
+  beforeEach(() => {
+    cwd = mkdtempSync(join(tmpdir(), 'agenthub-'));
+  });
+
+  afterEach(() => {
+    rmSync(cwd, { recursive: true, force: true });
+  });
+
+  it('creates and loads default config', () => {
+    const cfg = defaultConfig('test-project');
+    saveConfig(cwd, cfg);
+    const loaded = loadConfig(cwd);
+    expect(loaded.projectName).toBe('test-project');
+    expect(loaded.delegationMode).toBe('suggest');
+  });
+});