SwiftTUI 0.12.0

This minor release completes the control-style follow-ups and fixes layout,
input, animation, collection binding, and lifecycle defects across the hosts.
Public API additions include keyframe-builder control-flow overloads and the
FrameDropBlocker.taskTransfer diagnostic case. No ordinary public symbols
were removed since 0.11.3.

Added

• Bare-keyframe builders support conditionals, loops, and multi-case switches
  while preserving sequential timing, including empty loops.

Fixed

• Nested menus, popovers, and sheets share presentation ordering with input
  routing, modal focus, Escape dismissal, and focus restoration.
• Duplicate-ID ForEach bindings resolve the intended occurrence after
  collection edits. Bindings to removed occurrences cannot overwrite a
  surviving row; versioned lookup avoids repeated indexing for state-backed
  collections.
• Visible lazy-list rows preserve appearance and running tasks when their
  backing nodes change. Task ownership transfers at commit, with safe
  completion handling and cancellation when the row eventually departs.
• Body-producing styles update stored dynamic properties before evaluating
  makeBody, including mutations captured by actions and per-control state.
• Closed ControlGroups with value-only state survive enclosing lazy-tab
  dormancy. Menu content retains state and running tasks across style changes;
  omitted content cancels tasks and restarts them on return.
• Scroll drawing and hit testing use the viewport chosen by layout. Overlay
  indicators no longer compete for the corner cell, and inline menus keep
  their Escape handler and keyboard dismissal focus when disabled.
• Wrapped custom layouts retain alignment answers, and each placement pass
  evaluates alignment hooks once. Custom layouts named Group or EmptyView
  retain their own measurement and placement behavior.
• Spacer-only overlays distribute stack surplus correctly, flexible safe-area
  insets advertise their flexibility, and bounded stacks reserve later
  children's minimum sizes before distributing a deficit.
• Synthetic text-field carets mark the current glyph, including wide and
  masked text. Hover handlers receive exit callbacks when their view or
  modifier disappears, and Escape respects the focused navigation stack.
• Indeterminate progress indicators animate while idle and cancel their tick
  task on removal. Reduced-motion and determinate indicators remain static.
• Stepper input checks the live binding and current bounds before adjusting,
  so inactive controls do not rewrite out-of-range values.
• Deadline-driven gestures deliver updates with their authored transaction.
  Explicit transaction metadata takes precedence over stored binding animation,
  and termination and wheel handlers update the correct focus owner.
• Interrupted insertion and matched-geometry removal start from their visible
  geometry. Geometry-changing animations render their arrival and final frame;
  clipped offset descendants remain visible where their content intersects.
• Removed animation slots discard stale velocity, and completed transitions
  release curve registrations once their final consumer finishes.
• Scroll-position registrations retire with their owner. Live input streams
  adopt changed mouse-coordinate modes without discarding buffered input.
• Capsule tile fills and curved strokeBorder backgrounds respect their
  geometry. Narrow table cells truncate oversized graphemes without shifting
  separators, and rich-text decoration clearing has additional regression
  coverage.
• Layout diagnostics accumulate work across late-preference reconciliation
  passes and budget fallback paths.

Changed

• All style erasers share storage and reuse comparison. Body resolution,
  optional routes, and slider/stepper key and wheel registration share their
  respective implementations.
• Scroll validation reports the presentation variant as well as its style.
  Slider fixture SPI adds the same argument ordering as Stepper fixtures,
  retaining the existing initializer.

Full changelog

The coordinated 0.12 release was completed as 0.12.1 after correcting an outdated GIF-editor layout test. The 0.12.0 tags remain unchanged; no 0.12.0 site or organization tag was created.