chore(db): finish Prisma cutover to Drizzle Kit tooling

Move CMS SQL to drizzle/migrations, drop prisma packages/schema, wire drizzle-kit scripts, and regenerate schema names from src/db/schema.ts.

Co-authored-by: Cursor <[email protected]>

src/lib/proxy-auth-contract.test.ts

@@ -9,7 +9,7 @@ describe("proxy authentication boundary", () => {
 		expect(proxy).toContain('from "@/lib/proxy-auth"');
 		expect(proxy).not.toContain('from "@/lib/auth"');
 		expect(proxyAuth).not.toMatch(
-			/from\s+["'][^"']*(prisma|site-settings|credentials)[^"']*["']/i,
+			/from\s+["'][^"']*(db|site-settings|credentials|prisma)[^"']*["']/i,
 		);
 	});
 });