Refine map assistant controls

[SebastianBoehler]

Summary

• removes the map screen header/description so the map owns the view
• moves search into a rounded bottom floating control with a prominent Ask AI action
• keeps destination results compact as selectable chips and avoids repeating address details
• lets the AI action work even without a selected destination by pre-filling a nearby-location prompt

Closes #24

Verification

• /tmp/studyos-tools/flutter/bin/flutter analyze
• /tmp/studyos-tools/flutter/bin/flutter test test/maps_controls_test.dart test/navigation_test.dart test/map_location_models_test.dart
• /tmp/studyos-tools/flutter/bin/flutter test

[SebastianBoehler]

No blocking findings from this pass. I tried to submit this as an approving review, but GitHub rejected it because the authenticated account is treated as the PR author, so leaving it as a PR comment instead.

The PR stays tightly scoped to issue #24: the map becomes the primary canvas, the search/results controls move into compact bottom overlays, and the existing onAskAssistant handoff is reused rather than adding a second assistant path.

Likely risk areas I checked:

• layout constraints around MapsView now returning a Stack directly
• bottom overlay behavior in the existing AgentHomeScaffold safe-area/body structure
• selected-location actions, especially Ask AI and external maps
• regression coverage for compact results and navigation into the maps view

Local verification run from flutter_app:

• /tmp/studyos-tools/flutter/bin/flutter analyze
• /tmp/studyos-tools/flutter/bin/flutter test test/maps_controls_test.dart test/navigation_test.dart test/map_location_models_test.dart
• /tmp/studyos-tools/flutter/bin/flutter test

Concrete next steps: wait for the GitHub Flutter CI check to finish, then this looks reasonable for human review/merge. The only small follow-up I would consider is a focused widget test for MapsView/onAskAssistant when no destination is selected, because that generic nearby-location prompt is new behavior in this PR; I would not block this PR on it unless the team wants stricter coverage before merge.

[MertOkur]

lgtm

[SebastianBoehler]

Follow-up update from the Discord feedback:

• map view now opts out of the centered 760px app content shell and expands edge-to-edge
• search control uses the wider full-width bottom overlay
• Ask AI is now an icon-only round action inside the search field suffix, shown only while the search field is focused
• map rotation gestures are disabled to keep the map orientation stable

Verification rerun:

• /tmp/studyos-tools/flutter/bin/flutter analyze
• /tmp/studyos-tools/flutter/bin/flutter test test/maps_controls_test.dart test/navigation_test.dart test/map_location_models_test.dart
• /tmp/studyos-tools/flutter/bin/flutter test

[SebastianBoehler]

Moved the follow-up map refinement feedback into stacked PR #26 so this PR stays focused on the original issue #24 implementation.