fix(ci): resolve hoisted vitest binary in node:sqlite test step

bunx resolves vitest from the cwd's node_modules. In bun workspaces
vitest is hoisted to the monorepo root, so packages/app-core/node_modules/vitest
doesn't exist. Invoke vitest directly via the repo-root path that's
guaranteed to exist after a top-level install.

Author: Shaw

.github/workflows/test.yml

@@ -99,7 +99,7 @@ jobs:
         # minimal config that doesn't have the exclude.
         working-directory: packages/app-core
         run: |
-          bunx vitest run --config vitest.node-sqlite.config.ts
+          node ../../node_modules/vitest/vitest.mjs run --config vitest.node-sqlite.config.ts
 
   client-tests:
     name: Client Tests