Description

This PR delivers the v61 in-app widgets redesign:

1. Replaces the full-screen widget list, preview and edit screens with a single bottom sheet that navigates list → preview → edit, on a darker sheet background per the v61 design.
2. Adds a two-size system (small / wide) chosen on the preview carousel and persisted per widget, with a 2-column home grid where small widgets pair side-by-side and wide widgets span the full width.
3. Reworks editing mode into a dashed-border overlay with centered actions and drag-and-drop reordering that updates live as a widget is dragged over a cell.
4. Implements the interactive compact calculator, lifting the number pad into a full-width bar pinned to the bottom of the screen so it works at either size.
5. Adds the Bitkit Suggestions tile to the Add Widget gallery and its preview.
6. Adds the redesigned "Hello, Widgets" onboarding with "View & Organize" and "Add Widget" actions.
7. Handles the widgets-disabled state: the Add Widget sheet dims and blocks selection of tiles and shows an "Enable In Settings" button, and the widgets entry points route accordingly — onboarded with widgets enabled lands on the home widgets page, while disabled opens the Add Widget sheet (consistent across the drawer and "View & Organize", matching Android).
8. Updates the default widget set to Suggestions, Price (wide), Blocks · Facts (compact pair), Weather · Calculator (compact pair), News (wide).

It also removes the now-unused per-widget preview/list/detail/edit screens.

Linked Issues/Tasks

• Closes [Feature]: add compact widget support in app #566
• Closes [Feature]: add widget intro and add-widget grid #567

Screenshot / Video

QA Notes

Manual Tests

• 1. Home Widgets → Add Widget → tap a widget → swipe carousel to SMALL → Save Widget: widget appears half-width, paired with the next small widget.
• 2. Add Widget → tap a widget → WIDE page → Save Widget: widget spans the full grid width.
• 3. Preview (Price/Headlines/Blocks/Weather) → Widget Settings → toggle fields → back: choices persist; Facts/Calculator/Suggestions show no settings row.
• 4a. Home Widgets → enter editing → each widget shows dashed border + delete/settings/move icons.
  • 4b. drag a widget by the move handle over another cell (and into a gap): order updates live and persists.
  • 4c. trash → confirm: widget removed; settings: opens that widget's preview.
• 5a. Add a SMALL calculator → tap the ₿ or $ row: full-width number pad slides up at the bottom, tab bar hides, the calculator lifts above the keypad; typing updates both fields.
  • 5b. tap outside / drag down: keypad dismisses and content returns.
  • 5c. regression: WIDE calculator: keypad behavior and conversions unchanged.
• 6. Add Widget → Bitkit Suggestions tile shows the suggestion cards → tap → preview → Save Widget adds it.
• 7a. Onboarding → View & Organize (widgets enabled): lands on the home Widgets page.
  • 7b. Drawer → Widgets (onboarded, enabled): lands on the home Widgets page.
• 8a. Settings → disable widgets → Add Widget sheet: tiles dimmed/non-tappable, "Enable In Settings" routes to Widgets settings.
  • 8b. Onboarding → View & Organize and Drawer → Widgets (disabled): open the Add Widget sheet, not the hidden home page.
• 9. regression: upgrade from a build with saved widgets: existing widgets render (default wide) and the grid lays out correctly; fresh install/reset shows the new default set.

Automated Checks

• Build: xcodebuild -project Bitkit.xcodeproj -scheme Bitkit -configuration Debug -destination 'platform=iOS Simulator,id=<iPhone 16>' build ONLY_ACTIVE_ARCH=YES passes locally. Active-arch is required because the default x86_64 simulator slice fails to link the Rust FFI, unrelated to these changes.
• SwiftFormat: clean on the touched files.
• CI: standard build/test checks run by the PR bot.