fix(ci): ignore vitest temp workspace dirs in eslint

Vitest creates .tmp-fn-vitest-workspace-resolution-* directories
containing built JS files that ESLint scans as source, producing
~9500 false-positive no-undef errors that mask real lint issues.

Added .tmp-fn-*/** to global ignores. These dirs are already in
.gitignore but ESLint doesn't read .gitignore by default.

eslint.config.mjs

@@ -32,6 +32,8 @@ export default tseslint.config(
       // Project metadata (fn data, worktrees, etc.)
       ".fusion/**",
       ".worktrees/**",
+      // Vitest temporary workspace resolution directories
+      ".tmp-fn-*/**",
       ".claude/**",
       // Lock files
       "*.lock",