Dev build 44 (cf76942)

Development build 44 of commit cf76942. Not for production.
The iOS file is unsigned and must be re-signed before it can be installed; the Android APK is signed with a debug key.

fix(nav): never strand a page without a way back

Pages outside the tab shell (spot, add spot, login, register, admin)
could be alone on the stack: after creating a spot (context.go), after
logging in, or when opened from a link. Flutter then shows no back
button and Android's back closes the app.

• BackOrHomeButton: their app bars pop when possible, else go to the
  home map; BackToHomeScope does the same for the system back.
• A created spot replaces the add-spot form, so back leads to the map.
• Login opened from a page pops back to it; only the auth redirect
  (from=) moves on to the asked-for page. Login <-> register replace
  each other instead of resetting the stack.

Co-Authored-By: Claude Opus 5.5 noreply@anthropic.com
Claude-Session: https://claude.ai/code/session_018fB6JLL3879xPuqGgCmbwt