feat(mosaic): migrate install wizard from v0 to v1 (#103)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

packages/mosaic/src/runtime/mcp-config.ts

@@ -0,0 +1,95 @@
+import { readFileSync, writeFileSync, existsSync, mkdirSync } from 'node:fs';
+import { join, dirname } from 'node:path';
+import { homedir } from 'node:os';
+import type { RuntimeName } from '../types.js';
+
+const MCP_ENTRY = {
+  command: 'npx',
+  args: ['-y', '@modelcontextprotocol/server-sequential-thinking'],
+};
+
+export function configureMcpForRuntime(runtime: RuntimeName): void {
+  switch (runtime) {
+    case 'claude':
+      return configureClaudeMcp();
+    case 'codex':
+      return configureCodexMcp();
+    case 'opencode':
+      return configureOpenCodeMcp();
+  }
+}
+
+function ensureDir(filePath: string): void {
+  mkdirSync(dirname(filePath), { recursive: true });
+}
+
+function configureClaudeMcp(): void {
+  const settingsPath = join(homedir(), '.claude', 'settings.json');
+  ensureDir(settingsPath);
+
+  let data: Record<string, unknown> = {};
+  if (existsSync(settingsPath)) {
+    try {
+      data = JSON.parse(readFileSync(settingsPath, 'utf-8')) as Record<string, unknown>;
+    } catch {
+      // Start fresh if corrupt
+    }
+  }
+
+  if (
+    !data['mcpServers'] ||
+    typeof data['mcpServers'] !== 'object' ||
+    Array.isArray(data['mcpServers'])
+  ) {
+    data['mcpServers'] = {};
+  }
+  (data['mcpServers'] as Record<string, unknown>)['sequential-thinking'] = MCP_ENTRY;
+
+  writeFileSync(settingsPath, JSON.stringify(data, null, 2) + '\n', 'utf-8');
+}
+
+function configureCodexMcp(): void {
+  const configPath = join(homedir(), '.codex', 'config.toml');
+  ensureDir(configPath);
+
+  let content = '';
+  if (existsSync(configPath)) {
+    content = readFileSync(configPath, 'utf-8');
+    // Remove existing sequential-thinking section
+    content = content
+      .replace(/\[mcp_servers\.(sequential-thinking|sequential_thinking)\][\s\S]*?(?=\n\[|$)/g, '')
+      .trim();
+  }
+
+  content +=
+    '\n\n[mcp_servers.sequential-thinking]\n' +
+    'command = "npx"\n' +
+    'args = ["-y", "@modelcontextprotocol/server-sequential-thinking"]\n';
+
+  writeFileSync(configPath, content, 'utf-8');
+}
+
+function configureOpenCodeMcp(): void {
+  const configPath = join(homedir(), '.config', 'opencode', 'config.json');
+  ensureDir(configPath);
+
+  let data: Record<string, unknown> = {};
+  if (existsSync(configPath)) {
+    try {
+      data = JSON.parse(readFileSync(configPath, 'utf-8')) as Record<string, unknown>;
+    } catch {
+      // Start fresh
+    }
+  }
+
+  if (!data['mcp'] || typeof data['mcp'] !== 'object' || Array.isArray(data['mcp'])) {
+    data['mcp'] = {};
+  }
+  (data['mcp'] as Record<string, unknown>)['sequential-thinking'] = {
+    type: 'local',
+    command: ['npx', '-y', '@modelcontextprotocol/server-sequential-thinking'],
+    enabled: true,
+  };
+
+  writeFileSync(configPath, JSON.stringify(data, null, 2) + '\n', 'utf-8');
+}