Leave generic KML transport profiles unassigned

[stef-k]

Summary

• leave generic third-party KML routes without an inferred transport profile
• stop treating descriptive KML route names as transport authority
• show one dismissible reminder in the Trip Editor after a successful generic route import
• preserve authoritative Wayfarer KML v2 profile binding

Closes #480

Validation

• focused generic parser/import/controller and native-v2 tests: 21 passed, 0 failed, 0 skipped
• focused review selection: 30 passed, 0 failed
• Debug build: passed with 0 warnings and 0 errors
• LOC policy: passed; warnings limited to unchanged files
• git diff --check: passed

Database notes

No migration or trigger change. Generic routes use the existing empty-mode contract, under which TR_Segments_TransportProfile keeps TransportProfileId null.

UI notes

No modal or new notification framework. The existing dismissible TempData/layout alert is used once after redirect to the imported Trip Editor.