feat(seals): default Add/Edit seal type via REACT_APP_DEFAULT_SEAL_TYPE
requested to merge KKsurendran06/etir-national-application:fix/ena-293-default-seal-mechanical into dev-1.0.3
Fixes #289
The seal type dropdown was blank when adding a seal, so users had to pick "Mechanical" every time even though almost all TIR seals are mechanical.
Added an optional REACT_APP_DEFAULT_SEAL_TYPE env var (mechanical, electronic, or empty). When set, the Add/Edit seal dropdown defaults to that type. Editing keeps a seal's existing type, and empty = old behavior (blank)
Tested: on the EU instance with REACT_APP_DEFAULT_SEAL_TYPE=mechanical; Add seal now opens with Mechanical pre-selected.
Edited by KK Surendran