fix(lint): close type-check gaps in client scripts and tooling

Remove unused import flagged by CI lint, then harden the toolchain so
such issues are caught before push:

- lint-staged now also matches .tsx/.jsx (previously .tsx files skipped
  the pre-commit eslint pass, which is how the error reached CI)
- eslint ignores generated client bundles (gitignored, not worth linting)
- typecheck now also runs the client tsconfig; the hand-written browser
  source was excluded from the root config and never type-checked
- consolidate the window global augmentations (showToast,
  parseJsonResponseOrThrow) into a single client globals.d.ts; the inline
  declare-global blocks failed (non-module files) and masked real errors

Co-Authored-By: Claude Opus 4.7 <[email protected]>

eslint.config.mjs

@@ -2,7 +2,7 @@ import prettier from "eslint-config-prettier";
 import tseslint from "typescript-eslint";
 
 export default tseslint.config(
-  { ignores: ["dist/", "coverage/"] },
+  { ignores: ["dist/", "coverage/", "src/scripts/generated/"] },
   ...tseslint.configs.recommended,
   prettier,
   {