fix(settings): correct the MCP token scope note to match the write toggle

The note above the write toggle claimed tokens are read-only in every
case, which the toggle directly below it contradicts by minting a
read_write scope. Rewrite it to state the real model: read-only by
default, write opt-in per token, never admin. Resolve the pronoun that
read as a formal address, and promote both scope notes to foreground so
this security copy no longer renders as muted meta.

src/components/settings/mcp-section.tsx

@@ -340,7 +340,7 @@ function McpTokensCard() {
       <p className="text-sm">{t("settings.mcp.tokensDetail")}</p>
 
       <div className="space-y-4">
-        <p className="text-muted-foreground text-xs leading-relaxed">
+        <p className="text-sm leading-relaxed">
           {t("settings.mcp.scopeNote")}
         </p>
 
@@ -355,7 +355,7 @@ function McpTokensCard() {
               aria-label={t("settings.mcp.writeScopeToggleLabel")}
             />
           </div>
-          <p className="text-muted-foreground text-xs leading-relaxed">
+          <p className="text-sm leading-relaxed">
             {t("settings.mcp.writeScopeNote")}
           </p>
         </div>