feat: US-002 — SQLite + Drizzle ORM schema and migrations

- Install better-sqlite3 + drizzle-orm as runtime deps; drizzle-kit + @types/better-sqlite3 as devDeps
- Define 5 tables in src/main/db/schema.ts: clients, projects, tasks, checkpoints, notes
- All IDs are TEXT (UUID); types inferred via InferSelectModel/InferInsertModel
- initDb() in src/main/db/index.ts opens adiuva.db at app.getPath('userData'), runs CREATE TABLE IF NOT EXISTS (non-destructive push), enables WAL mode
- Call initDb() in main process app ready handler
- Externalize better-sqlite3 in vite.main.config.mts; add AutoUnpackNativesPlugin to forge.config.ts
- Add drizzle.config.ts for drizzle-kit CLI support

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

forge.config.ts

@@ -3,6 +3,7 @@ import { MakerSquirrel } from '@electron-forge/maker-squirrel';
 import { MakerZIP } from '@electron-forge/maker-zip';
 import { MakerDeb } from '@electron-forge/maker-deb';
 import { MakerRpm } from '@electron-forge/maker-rpm';
+import { AutoUnpackNativesPlugin } from '@electron-forge/plugin-auto-unpack-natives';
 import { VitePlugin } from '@electron-forge/plugin-vite';
 import { FusesPlugin } from '@electron-forge/plugin-fuses';
 import { FuseV1Options, FuseVersion } from '@electron/fuses';
@@ -19,6 +20,7 @@ const config: ForgeConfig = {
     new MakerDeb({}),
   ],
   plugins: [
+    new AutoUnpackNativesPlugin({}),
     new VitePlugin({
       // `build` can specify multiple entry builds, which can be Main process, Preload scripts, Worker process, etc.
       // If you are familiar with Vite configuration, it will look really familiar.