The contributor PR adds useful Windows terminal and portable mode support, but it also reintroduced an older General settings zoom block and left the new native settings paths without enough regression coverage. This commit keeps the feature direction intact while removing the duplicate UI, making invalid bash paths fail at save time, and covering the portable cache and app-mode paths with focused tests.
Constraint: This commit lands directly on the contributor PR branch to avoid a long review-comment loop.
Rejected: Ask the contributor to rework the PR from scratch | the remaining issues are narrow and maintainable by us.
Confidence: high
Scope-risk: moderate
Directive: Keep future portable-mode changes covered at the native boundary and the desktop store boundary.
Tested: cd desktop && bun run test src/pages/TerminalSettings.test.tsx src/__tests__/generalSettings.test.tsx src/stores/settingsStore.test.ts
Tested: bun test src/utils/__tests__/cachePaths.test.ts
Tested: cd desktop/src-tauri && cargo test
Tested: cd desktop && bun run lint
Tested: cd desktop/src-tauri && cargo check
Tested: bun run check:server
Tested: bun run check:desktop
Not-tested: Manual Windows packaged-app portable-mode smoke; to be covered before a future release.
