fix: resolve all lint errors — exclude generated dirs, auto-fix source

Exclude drizzle/ and .planning/ from Biome (generated files with
incompatible formatting). Auto-fix import ordering and formatting
in existing source files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/services/thread.service.test.ts

@@ -434,7 +434,10 @@ describe("Thread Service", () => {
 		});
 
 		it("returns { success: false, error } when thread status is 'resolved'", () => {
-			const thread = createThread(db, { name: "Resolved Thread", categoryId: 1 });
+			const thread = createThread(db, {
+				name: "Resolved Thread",
+				categoryId: 1,
+			});
 			const candidate = createCandidate(db, thread.id, {
 				name: "Winner",
 				categoryId: 1,