Apply technical-light design system to the gateway dashboard

Restyles the Blazor dashboard onto a portable token-based theme so it
reads like an instrument panel: warm-paper background, hairline-ruled
panels, IBM Plex type, monospace tabular numerics, and status carried by
colour chips. Vendors theme.css + IBM Plex fonts, rewrites dashboard.css
as a thin token-driven view layer, and swaps the Bootstrap navbar and
status badges for the design-system app bar and chips.

Also includes pending API-key management, Galaxy hierarchy projection,
and constraint-enforcement work with their tests.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/MxGateway.Server/Dashboard/Components/Shared/StatusBadge.razor

@@ -1,4 +1,4 @@
-<span class="badge @CssClass">@Text</span>
+<span class="chip @CssClass">@Text</span>
 
 @code {
     [Parameter]
@@ -6,12 +6,11 @@
 
     private string CssClass => Text switch
     {
-        "Ready" or "Healthy" => "text-bg-success",
-        "Creating" or "StartingWorker" or "WaitingForPipe" or "InitializingWorker" or "Closing" => "text-bg-info",
-        "Closed" => "text-bg-secondary",
-        "Stale" => "text-bg-warning",
-        "Faulted" or "Unavailable" => "text-bg-danger",
-        "Unknown" => "text-bg-light text-dark border",
-        _ => "text-bg-light text-dark border"
+        "Ready" or "Healthy" or "Active" => "chip-ok",
+        "Creating" or "StartingWorker" or "WaitingForPipe" or "InitializingWorker" or "Closing" => "chip-warn",
+        "Stale" or "Degraded" => "chip-warn",
+        "Faulted" or "Unavailable" => "chip-bad",
+        "Closed" or "Revoked" or "Unknown" => "chip-idle",
+        _ => "chip-idle"
     };
 }