fix(map-view): preserve scroll position and other magic scrolling UX tricks

[simon-the-shark]

hopefully for the better :P

[greptile-apps]

Greptile Summary

elo żelo solvrowiczu 👋

This PR overhauls the map bottom-sheet scroll UX by capturing the sheet expansion and list scroll offset just before a marker is activated, then restoring them after deactivation via a post-frame retry loop (_SheetPositionRestorer). It also removes animated_list_plus in favour of a plain SliverList.builder to avoid scroll-extent collapse during list transitions, bumps Flutter to 3.44.6, and fixes a DST-sensitive date-range iteration in the calendar.

• Scroll/sheet preservation: usePreservedSheetPosition now captures offset + size on marker activation and restores them (with animated restore for parkings, instant for multilayer) on deactivation; tab index is also preserved via pendingTabIndex on DraggableScrollableController.
• ActiveMapItemSliver: active marker content is rendered as a SliverToBoxAdapter (not a SliverList) and NeverScrollableScrollPhysics is applied while a marker is active, preventing the prior list offset from being clamped mid-animation.
• Calendar DST fix: _generateDateRange now uses DateTime(y, m, d + 1) instead of add(Duration(days: 1)), correctly crossing DST boundaries without skipping or doubling a day.

Confidence Score: 5/5

Safe to merge — the core restore logic is well-guarded with attachment/hasClients checks and a capped retry budget; no data loss or broken navigation paths identified.

All changes are additive UX improvements or clean-up. The scroll/sheet preserve-and-restore logic has appropriate isAttached/hasClients guards and bounded retry counts, errors are surfaced via FlutterError.reportError, and the calendar DST fix is straightforwardly correct. No changes to data persistence, auth, or network layers.

lib/features/bottom_scroll_sheet/hooks/use_preserved_scroll_offset.dart — the new _SheetPositionRestorer has no cancellation mechanism for concurrent restorers on rapid user taps, and the T == Parking type dispatch couples domain logic into generic restore code.

Important Files Changed

Filename	Overview
lib/features/bottom_scroll_sheet/hooks/use_preserved_scroll_offset.dart	New hook preserving sheet expansion and scroll offset across marker activation; uses post-frame retry loop (_SheetPositionRestorer) with proper error reporting but no cancellation path
lib/features/map_view/controllers/bottom_sheet_controller.dart	Adds Expando-backed state (preservedPosition, lastSyncedTabIndex, pendingTabIndex) and safe animation helpers to the DraggableScrollableController extension; clean design
lib/features/bottom_scroll_sheet/use_tab_scroll_sync.dart	Adds tab-index restore on remount via takePendingTabIndex/useMemoized, syncs lastSyncedTabIndex on every scroll update, and simplifies the ensureVisible overshoot workaround
lib/features/map_view/controllers/map_controller.dart	Activation path now only calls resetSafe on activation, delegating sheet restoration to usePreservedSheetPosition on deactivation; background tap also skips resetSafe when an item was active
lib/features/bottom_scroll_sheet/map_data_sheet_list.dart	Uses the new usePreservedSheetPosition hook, switches to ActiveMapItemSliver when a marker is active, sets NeverScrollableScrollPhysics while an item is active to prevent offset clamping
lib/features/calendar/bussiness/get_events_per_days_use_case.dart	Fixes DST-sensitive date iteration: replaces add(Duration(days:1)) with DateTime constructor increment, correctly advancing the calendar day boundary across DST transitions
lib/features/bottom_scroll_sheet/active_map_item_sliver.dart	New StatelessWidget rendering the selected marker tile as a SliverToBoxAdapter (avoids SliverList scroll-extent collapse bug)
lib/features/bottom_scroll_sheet/data_list.dart	Removes SliverImplicitlyAnimatedList and animated_list_plus dependency in favour of plain SliverList.builder; simplifies _DataSliverList to StatelessWidget
lib/features/bottom_scroll_sheet/map_view_pop_behaviour.dart	Back-button handler now skips resetSafe when a marker was active, matching the new restore flow; only resets when there is no active item to restore

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant User
    participant MapController
    participant usePreservedSheetPosition
    participant BottomSheetController
    participant SheetPositionRestorer

    User->>MapController: tap marker (activate)
    MapController->>BottomSheetController: resetSafe()
    MapController->>usePreservedSheetPosition: "activeMarker prev=null → next=item"
    usePreservedSheetPosition->>BottomSheetController: "preservedPosition = {offset, sheetSize, tabIndex}"
    usePreservedSheetPosition->>ScrollController: jumpTo(0)

    User->>MapController: tap marker (deactivate)
    MapController->>usePreservedSheetPosition: "activeMarker prev=item → next=null"
    usePreservedSheetPosition->>BottomSheetController: clearPreservedPosition()
    usePreservedSheetPosition->>BottomSheetController: "pendingTabIndex = position.tabIndex"
    usePreservedSheetPosition->>SheetPositionRestorer: start() → schedulePostFrame

    SheetPositionRestorer->>BottomSheetController: animateToSafe / jumpToSafe (sheet size)
    SheetPositionRestorer->>ScrollController: jumpTo(savedOffset)

    Note over SheetPositionRestorer: Retries up to 12× if sheet/scroll not ready yet

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%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
sequenceDiagram
    participant User
    participant MapController
    participant usePreservedSheetPosition
    participant BottomSheetController
    participant SheetPositionRestorer

    User->>MapController: tap marker (activate)
    MapController->>BottomSheetController: resetSafe()
    MapController->>usePreservedSheetPosition: "activeMarker prev=null → next=item"
    usePreservedSheetPosition->>BottomSheetController: "preservedPosition = {offset, sheetSize, tabIndex}"
    usePreservedSheetPosition->>ScrollController: jumpTo(0)

    User->>MapController: tap marker (deactivate)
    MapController->>usePreservedSheetPosition: "activeMarker prev=item → next=null"
    usePreservedSheetPosition->>BottomSheetController: clearPreservedPosition()
    usePreservedSheetPosition->>BottomSheetController: "pendingTabIndex = position.tabIndex"
    usePreservedSheetPosition->>SheetPositionRestorer: start() → schedulePostFrame

    SheetPositionRestorer->>BottomSheetController: animateToSafe / jumpToSafe (sheet size)
    SheetPositionRestorer->>ScrollController: jumpTo(savedOffset)

    Note over SheetPositionRestorer: Retries up to 12× if sheet/scroll not ready yet

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