Stability & UX polish

[v1.1.0] - 2025-12-02

Added

• Copy/download actions for the XML pane with status hints; first entry auto-loads and last-viewed section persists per file.
• Upload page UX: client-side extension/size checks (≤10 MB), inline errors, loading hint, and resume link (best-effort if storage is allowed).
• Local Bootstrap 5.3.2 and FontAwesome 6.4.0 assets to avoid tracking-prevention issues.

Changed

• Light server guardrails: basic extension/size checks and friendly messages; PHP upload/post limits set to 10 MB in the container.