HUD Shelf v0.3.1 Release

Edit-mode outline fixes found during first-consumer integration
(Hydrate or Diedrate and HUD Clock).

Fixed

• Outline render order raised from 0.99 to 1.01. VS's
  GuiManager renders registered dialogs at 1.0, so the previous
  order buried outlines beneath any dialog with an opaque background.
  The outline now reliably renders on top of all HUDs; the early-exit
  when edit mode is off keeps cost zero outside edit mode.
• Outline dimensions now derived from GetBounds() centered
  within the composer footprint rather than taken directly from
  SingleComposer.Bounds.OuterWidth/Height. For dialogs built with
  WithFixedPadding, OuterWidth/Height includes the padding on
  both sides, which pushed the outline visibly outside the panel
  edge. The new formula left = absX + (OuterWidth − bw) / 2
  places the outline at the panel boundary for any dialog with
  symmetric padding without requiring HudShelf to know the padding
  value.
• Thin-HUD outline now has 2 px of outward padding so it remains
  visible on very short elements such as stat bars (10 px fixedHeight
  composes to ~15 px at 1.5× GUI scale — a 2 px border on 15 px
  was nearly invisible without the pad).
• Composer-unavailable fallback in the outline loop now derives
  position from CurrentPosition + GetBounds() via SnapMath when
  TryGetHudRect fails, so a HUD whose SingleComposer is null or
  whose root element is a wrapper still gets an outline.