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/config/config-service.ts

@@ -0,0 +1,23 @@
+import type { SoulConfig, UserConfig, ToolsConfig, InstallAction } from '../types.js';
+import { FileConfigAdapter } from './file-adapter.js';
+
+/**
+ * ConfigService interface — abstracts config read/write operations.
+ * Currently backed by FileConfigAdapter (writes .md files from templates).
+ * Designed for future swap to SqliteConfigAdapter or PostgresConfigAdapter.
+ */
+export interface ConfigService {
+  readSoul(): Promise<SoulConfig>;
+  readUser(): Promise<UserConfig>;
+  readTools(): Promise<ToolsConfig>;
+
+  writeSoul(config: SoulConfig): Promise<void>;
+  writeUser(config: UserConfig): Promise<void>;
+  writeTools(config: ToolsConfig): Promise<void>;
+
+  syncFramework(action: InstallAction): Promise<void>;
+}
+
+export function createConfigService(mosaicHome: string, sourceDir: string): ConfigService {
+  return new FileConfigAdapter(mosaicHome, sourceDir);
+}