Add comprehensive test suite with CI workflow

- 211 tests across 15 files covering services (tracking, discovery,
  metadata, backup, credits, webhooks, settings, update-check, colors,
  person), utilities (config, cron, providers, title-theme), and TMDB
  image URL helpers
- `lib/test-preload.ts` + `bunfig.toml` wire up a global in-memory
  SQLite DB with migrations for all DB-backed tests
- `lib/test-utils.ts` provides `clearAllTables()` and seed helpers
  (insertUser, insertTitle, insertTvShow, insertMovieWatch, etc.)
- Export `getBackupSource`, `isKnownBackup`, `isValidBackupFilename`,
  `buildBackupCron`, `performUpdateCheck` internals for direct testing
- GitHub Actions workflow runs `bun test --coverage` on push/PR to main

lib/providers.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, test } from "bun:test";
+import { generateProviderUrl } from "./providers";
+
+describe("generateProviderUrl", () => {
+  test("generates Netflix URL", () => {
+    expect(generateProviderUrl(8, "Inception")).toBe(
+      "https://www.netflix.com/search?q=Inception",
+    );
+  });
+
+  test("generates Amazon Prime Video URL", () => {
+    expect(generateProviderUrl(9, "The Matrix")).toBe(
+      "https://www.amazon.com/s?i=instant-video&k=The%20Matrix",
+    );
+  });
+
+  test("generates Disney+ URL", () => {
+    expect(generateProviderUrl(337, "Frozen")).toBe(
+      "https://www.disneyplus.com/search/Frozen",
+    );
+  });
+
+  test("URL-encodes spaces", () => {
+    expect(generateProviderUrl(8, "The Dark Knight")).toBe(
+      "https://www.netflix.com/search?q=The%20Dark%20Knight",
+    );
+  });
+
+  test("URL-encodes special characters", () => {
+    expect(generateProviderUrl(8, "Tom & Jerry")).toBe(
+      "https://www.netflix.com/search?q=Tom%20%26%20Jerry",
+    );
+  });
+
+  test("URL-encodes unicode", () => {
+    const url = generateProviderUrl(8, "Amelie");
+    expect(url).toContain("Amelie");
+    expect(url).not.toBeNull();
+  });
+
+  test("returns null for unknown provider ID", () => {
+    expect(generateProviderUrl(99999, "Test")).toBeNull();
+  });
+
+  test("generates Hulu URL", () => {
+    expect(generateProviderUrl(15, "Test")).toBe(
+      "https://www.hulu.com/search?q=Test",
+    );
+  });
+});