Tune SQLite caches and maintain planner statistics

tests/unit/db-statements.test.ts

@@ -9,6 +9,23 @@ beforeEach(async () => {
 afterEach(async () => { await fixture.cleanup(); });
 
 describe('prepared statement caching', () => {
+    it('tunes the controller connection and stops periodic optimization when closed', async () => {
+        const { db, closeDb } = await import('../../src/lib/server/db/index.js');
+        vi.useFakeTimers({ toFake: ['setInterval', 'clearInterval'] });
+        try {
+            const handle = db();
+            expect(handle.pragma('cache_size', { simple: true })).toBe(-131072);
+            expect(handle.pragma('temp_store', { simple: true })).toBe(2);
+            expect(handle.pragma('journal_size_limit', { simple: true })).toBe(67108864);
+            const pragma = vi.spyOn(handle, 'pragma');
+            vi.advanceTimersByTime(60 * 60_000);
+            expect(pragma).toHaveBeenCalledWith('optimize');
+            pragma.mockClear();
+            closeDb();
+            vi.advanceTimersByTime(60 * 60_000);
+            expect(pragma).not.toHaveBeenCalled();
+        } finally { vi.useRealTimers(); }
+    });
     it('reuses statements with fresh parameters and remains usable after rollback', async () => {
         const { db } = await import('../../src/lib/server/db/index.js');
         const insertSql = 'INSERT INTO settings (key, value) VALUES (?, ?)';