refactor(web): dashboard typography & contrast pass

Removes the global `uppercase` + `font-mondwest` from the App.tsx root
that forced every page to opt-out, replaces stacked-alpha text colors
with semantic tokens for WCAG-AA contrast across all 7 themes, and
applies the new `text-display` utility from @nous-research/ui@0.16.0
on intentional brand chrome (page titles, sidebar headings, segmented
filters) only. Bumps every sub-12px arbitrary text size to text-xs.

Also widens the dashboard plugin routes (/api/dashboard/agent-plugins/
{name:path}/...) so category-namespaced plugins like observability/
langfuse and image_gen/openai can be enable/disabled from the dashboard
— previously the FE encodeURIComponent-ed the slash and the backend
{name} route rejected it. _validate_plugin_name still blocks .. and
backslash, and strips leading/trailing slash.

Touches sessions/env/keys page chrome and adds two new i18n keys
(`overview`, `showMore`/`showLess`) across all 18 locales.

Squashes 19 commits from PR #28832.

Co-authored-by: Hermes <noreply@nousresearch.com>

web/src/components/ui/card.tsx

@@ -1,4 +1,4 @@
-import { cn } from "@/lib/utils";
+import { cn, themedBody } from "@/lib/utils";
 
 /**
  * Themed card primitive. Themes can restyle every card without touching
@@ -27,6 +27,7 @@ export function Card({ className, style, ...props }: React.HTMLAttributes<HTMLDi
     <div
       className={cn(
         "border border-border bg-card/80 text-card-foreground w-full",
+        themedBody,
         className,
       )}
       style={{ ...CARD_STYLE, ...style }}
@@ -40,11 +41,21 @@ export function CardHeader({ className, ...props }: React.HTMLAttributes<HTMLDiv
 }
 
 export function CardTitle({ className, ...props }: React.HTMLAttributes<HTMLHeadingElement>) {
-  return <h3 className={cn("font-expanded text-sm font-bold tracking-[0.08em] uppercase blend-lighter", className)} {...props} />;
+  return (
+    <h3
+      className={cn(
+        "font-mondwest text-display text-sm tracking-[0.12em] text-text-primary",
+        className,
+      )}
+      {...props}
+    />
+  );
 }
 
 export function CardDescription({ className, ...props }: React.HTMLAttributes<HTMLParagraphElement>) {
-  return <p className={cn("font-mondwest text-xs text-muted-foreground", className)} {...props} />;
+  return (
+    <p className={cn("font-mondwest normal-case text-xs text-muted-foreground", className)} {...props} />
+  );
 }
 
 export function CardContent({ className, ...props }: React.HTMLAttributes<HTMLDivElement>) {

web/src/components/ui/confirm-dialog.tsx

@@ -2,7 +2,7 @@ import { useEffect, useRef } from "react";
 import { createPortal } from "react-dom";
 import { AlertTriangle } from "lucide-react";
 import { Button } from "@nous-research/ui/ui/components/button";
-import { cn } from "@/lib/utils";
+import { cn, themedBody } from "@/lib/utils";
 
 export function ConfirmDialog({
   cancelLabel = "Cancel",
@@ -64,6 +64,7 @@ export function ConfirmDialog({
       <div
         ref={dialogRef}
         className={cn(
+          themedBody,
           "relative w-full max-w-md mx-4",
           "border border-border bg-card shadow-lg",
           "animate-[dialog-in_180ms_ease-out]",
@@ -82,7 +83,7 @@ export function ConfirmDialog({
           <div className="flex-1 min-w-0 flex flex-col gap-1">
             <h2
               id="confirm-dialog-title"
-              className="font-expanded text-sm font-bold tracking-[0.08em] uppercase blend-lighter"
+              className="font-mondwest text-display text-sm font-bold tracking-[0.12em] blend-lighter"
             >
               {title}
             </h2>
@@ -90,7 +91,7 @@ export function ConfirmDialog({
             {description && (
               <p
                 id="confirm-dialog-desc"
-                className="font-mondwest text-xs text-muted-foreground leading-relaxed"
+                className="font-mondwest normal-case text-xs text-muted-foreground leading-relaxed"
               >
                 {description}
               </p>