Add Loader-Gated Upload Flow for Ticket Extraction

[cp89cyber]

Summary

• add inline processing loader, error messaging, and JS state helpers to gate the /add_ticket/ form until extraction completes
• keep existing field IDs untouched while hiding form/save elements by default and revealing them only after success or on error
• align stylesheet with the new loader and error visuals so mobile view stays compact

Testing

• Not run (not requested)