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

src/lib/server/db/index.ts

@@ -0,0 +1,22 @@
+import Database from 'better-sqlite3';
+import { drizzle } from 'drizzle-orm/better-sqlite3';
+import * as schema from './schema';
+import { existsSync, mkdirSync } from 'fs';
+import { dirname } from 'path';
+
+const DB_PATH = process.env.DATABASE_PATH || './data/taskplaner.db';
+
+// Ensure data directory exists
+const dbDir = dirname(DB_PATH);
+if (!existsSync(dbDir)) {
+	mkdirSync(dbDir, { recursive: true });
+}
+
+const sqlite = new Database(DB_PATH);
+
+// Enable WAL mode for better concurrent read performance
+sqlite.pragma('journal_mode = WAL');
+
+export const db = drizzle(sqlite, { schema });
+
+export { schema };

src/lib/server/db/schema.ts

@@ -0,0 +1,22 @@
+import { sqliteTable, text, integer } from 'drizzle-orm/sqlite-core';
+
+// Entry types: 'task' (actionable) or 'thought' (reference)
+export const entries = sqliteTable('entries', {
+	id: text('id').primaryKey(), // nanoid
+	title: text('title'),
+	content: text('content').notNull(),
+	type: text('type', { enum: ['task', 'thought'] }).notNull().default('thought'),
+	status: text('status', { enum: ['open', 'done', 'archived'] }).default('open'), // for tasks
+	pinned: integer('pinned', { mode: 'boolean' }).default(false),
+	dueDate: text('due_date'), // ISO date string, nullable
+	createdAt: text('created_at')
+		.notNull()
+		.$defaultFn(() => new Date().toISOString()),
+	updatedAt: text('updated_at')
+		.notNull()
+		.$defaultFn(() => new Date().toISOString())
+});
+
+// Type inference for TypeScript
+export type Entry = typeof entries.$inferSelect;
+export type NewEntry = typeof entries.$inferInsert;