chore: migrate monorepo toolchain pnpm+vitest → bun (bun test, bunfig preload, bun.lock)

- Gateway + backend + frontend: pnpm/vitest fully removed → bun 1.3.14
  (bun install, bun test tests/, bunfig.toml [test] preload, bun.lock).
- vitest configs deleted; vitest→bun facade (jest/mock/spyOn/waitForCompat)
  keeps the vitest-style assertions working under bun:test.
- flake.nix: bunInstall switch; pruned prod-pass now removes post-pnpm
  dev-toolchain trees; frontend builds Next standalone via bun's next.
- CI: deploy.yml installs with bun + runs bun test tests/ per service.
- 190 tests green (146 gateway + 37 backend pass, 14 skip), 0 fail;
  tsc + biome across all 3 services clean.

Co-authored-by: git-migration[bot] <noreply@gmw.local>

services/discord-gateway/tests/cacheBatchLookup.test.ts

@@ -6,12 +6,12 @@
 // single-key getter: unexpired rows only, malformed rows skipped, verdicts
 // normalized through the shared parser. The DB layer is mocked — no live
 // Postgres in unit tests.
-import { beforeEach, describe, expect, it, vi } from "vitest";
+import { beforeEach, describe, expect, it, jest, mock } from "bun:test";
 
-const executeAll = vi.fn();
-const executeGet = vi.fn();
+const executeAll = jest.fn();
+const executeGet = jest.fn();
 
-vi.mock("../src/shared/database/drizzle.js", () => ({
+mock.module("../src/shared/database/drizzle.js", () => ({
   executeAll: (...args: unknown[]) => executeAll(...args),
   executeGet: (...args: unknown[]) => executeGet(...args),
 }));

services/discord-gateway/tests/setup-env.ts

@@ -0,0 +1,7 @@
+// bun test preload — replicates the env block from the old vitest.config.ts.
+// Runs before any test module imports, so the config singleton (which reads
+// process.env at import time) gets the same test values it had under vitest.
+process.env.DISCORD_TOKEN = "test-discord-token";
+process.env.DATABASE_URL = "postgres://localhost:6432/test";
+process.env.AI_ANALYSIS_ENABLED = "true";
+process.env.AI_LLM_API_KEY = "sk-test";

services/discord-gateway/tests/tinyFishSearch.test.ts

@@ -45,7 +45,7 @@ describe("tinyFishSearch fallback", () => {
     // Pin the live config object to a known-disabled state: the shell may
     // export a real TINYFISH_API_KEY (dev box), which would flip
     // isTinyFishEnabled() and let tests hit the network.
-    const { config } = await import("../../src/shared/config/index.js");
+    const { config } = await import("../src/shared/config/index.js");
     prevKey = config.TINYFISH_API_KEY;
     prevEnabled = config.TINYFISH_SEARCH_ENABLED;
     (config as Record<string, unknown>).TINYFISH_API_KEY = "";
@@ -54,7 +54,7 @@ describe("tinyFishSearch fallback", () => {
 
   afterEach(async () => {
     vi.restoreAllMocks();
-    const { config } = await import("../../src/shared/config/index.js");
+    const { config } = await import("../src/shared/config/index.js");
     (config as Record<string, unknown>).TINYFISH_API_KEY = prevKey;
     (config as Record<string, unknown>).TINYFISH_SEARCH_ENABLED = prevEnabled;
   });
@@ -63,7 +63,7 @@ describe("tinyFishSearch fallback", () => {
     config: Record<string, unknown>;
     prev: string;
   }> {
-    const { config } = await import("../../src/shared/config/index.js");
+    const { config } = await import("../src/shared/config/index.js");
     const prev = config.TINYFISH_API_KEY;
     (config as Record<string, unknown>).TINYFISH_API_KEY = "sk-test-key";
     return { config: config as unknown as Record<string, unknown>, prev };