TASK 60: the border-colour drop-down names every colour

The creator: "under Live->Layers->webcam->Properties->border color: in the drop
down box, the #hex values are good, but add a corresponding color name/label next
to the value."

Each row now reads "#e94560  Crimson" - the hex stays exactly as it was, the
colour's name goes next to it (dimmed #a0a0b0 so the hex reads first), and the
tooltip becomes "Crimson (#e94560)".

The 14 colours were a hard-coded string[] inside the click handler - a list of
bare strings cannot carry a name, and a list hidden in UI code cannot be asserted
on. They now live in Models/BorderColorPalette.cs: NamedColor(Hex, Name) +
BorderColorPalette.All (the single source of truth) + NameOf(hex), which answers
case-insensitively and falls back to the hex for a colour outside the palette.
The picker builds its menu from the catalogue and no longer knows any colour by
heart.

The names are chosen not to collide - the palette has two greens, two blues and
two warm colours: #00FF00 is Lime and #22c55e Emerald, #0000FF is Blue and
#3b82f6 Azure, #FF8800 is Orange and #f59e0b Amber.

Guard: ytLive.Tests/BorderColorPaletteTests.cs - every entry valid + named, no
hex or name repeated, the 14 legacy colours all still offered, NameOf answers,
and the old list is gone from the handler. 433/433 green, 0 warnings.

ai.md

@@ -278,6 +278,11 @@ C# / WPF (.NET 8) following MVVM:
 - **Five-scene catalog (`Models/SceneCatalog.cs`):** the product is exactly Starting/Live/BRB/Chat/Ending — work with less, never more (the escape hatch for "more" is OBS). Scenes are matched **by name** (`SceneCatalog.Is`, case-insensitive trim). Empty DBs seed all five; the scenes-header "+" (`ShowAddScene`/`MissingScenes` on `MainViewModel`) only appears while ≥1 canonical scene is missing and its menu lists only the missing ones, re-adding them by name (`AddSceneCommand`). Renaming a canonical scene makes it missing again; `AddScene` rejects non-canonical names.
 - Theming: all custom styles live in `Themes/Controls.xaml`, merged in `App.xaml` — never duplicate styles per-window (dialog duplicates were consolidated into this dictionary). **Every control in the app carries a theme style (TASK 58, 2026-10-21):** an unstyled `ComboBox`/`CheckBox` falls back to the **light WPF system template** (grey border, system arrow, white popup list) and sticks out of the dark panels — the properties panel's drop-downs had been hand-painted with a `Background`/`Foreground` instead of a style (the chat Font drop-down was a copy of that), and every check box was default. The rule now: `ComboBox` → `YtComboBox`, `CheckBox` → `YtCheckBox`, the dense properties fields → `YtTextBoxCompact` (`BasedOn YtTextBox`: 11px, padding 4,2) — **no hand-painted `Background`/`BorderBrush` on a themed control**. `ytLive.Tests/PropertiesStyleTests.cs` is the guard: it fails if an unstyled drop-down, check box or properties field comes back
 - **The properties panel is a HIERARCHY (TASK 59, 2026-10-21):** a **title owns its content, and the content is indented one level (10px) under it** — the creator's ruling: *"the 'drag to move' help text needs to be indented under 'Mirror Rect' to show parentage … same with Geometry, Border Color, Border Thickness … Remove should be indented under Background as should Blur … Strength should be indented under Blur."* So the webcam's block reads `Shape` (the mirror switch + the shape choice) → `Geometry` → `Border Color` → `Border Thickness` → `Background` (Remove, Blur, and Strength one level deeper under Blur), each title SemiBold at 11px `#a0a0b0` like the existing ones. **The shape is a CHOICE, not a toggle button:** `IsRectShape`/`IsRoundShape` on `SceneElement` are two settable bools and the panel shows them as two `SegmentToggle` options (Rect | Circle) with **Rect selected by default** (an element that never picked a shape is a rect) — the old single button showed the *next* action ("Round"), which is why the creator could not tell what the camera was. The mutual exclusion lives in the MODEL (each setter flips through `ToggleClipShape()` and both props are re-raised), **not** in a WPF `RadioButton` group — a RadioButton group unchecks its siblings by setting `IsChecked` in code, which silently kills the binding (stackoverflow 7376373). Each setter always re-raises, so a refused write (the vertical Chat layout is rect-only) makes the UI snap back. Guard: `ytLive.Tests/PropertiesHierarchyTests.cs`
+- **One list for the offered colours (TASK 60):** the border-colour drop-down builds its menu from
+  `Models/BorderColorPalette.cs` (`NamedColor(Hex, Name)` + `NameOf(hex)`), NOT from a list inside
+  the click handler — the creator asked for a colour NAME next to each hex (`#e94560  Crimson`), and a
+  hard-coded `string[]` cannot carry one. A palette the creator may want to extend belongs in a
+  testable catalogue, with the UI as a consumer
 - Resolution tiers: 1080p60@8 (default) → 1080p30@8 → 720p60@6 → 720p30@6 → **Vertical 1080p60@8 (9:16, 1080×1920)**. The composition master frame is **always 1920×1080** — a tier is an output rect + target resolution over that master, so source geometry is never rewritten (no rounding drift). 16:9 tiers use the full frame; the vertical tier uses a centered **607×1080** window and the preview dims the cropped side strips at 55% black with an accent outline (semi-crop — the cut area stays visible). A resolution badge in the preview corner shows the active tier. Bottom bar: gear icon far left, stream stats (bitrate/FPS/dropped/duration) centered under preview, resolution dropdown far right. A **tooltip** explains finding upload bandwidth — an in-app speed test was deliberately dropped (unreliable). The future encoder crops the master to the rect and scales to the tier's Width×Height
 - Crash diagnosis: `AppLog` writes startup checkpoints to `%APPDATA%\ytLlive\startup.log`; `App.xaml.cs` logs `DispatcherUnhandledException`/`AppDomain.UnhandledException`. When WPF won't run from WSL, this log is how you find the failure (it caught the `MenuItemRole.Separator` XAML crash and the ComboBox SelectionBoxItem bug)