feat(01-01): configure Drizzle schema with entries table

- Schema with unified entries table (task/thought types)
- Fields: id, title, content, type, status, pinned, dueDate, timestamps
- Database connection with WAL mode
- Drizzle kit scripts (db:generate, db:migrate, db:push, db:studio)
- Database file at ./data/taskplaner.db

drizzle.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from 'drizzle-kit';
+
+export default defineConfig({
+	schema: './src/lib/server/db/schema.ts',
+	out: './drizzle',
+	dialect: 'sqlite',
+	dbCredentials: {
+		url: process.env.DATABASE_PATH || './data/taskplaner.db'
+	}
+});