Simplify Dashboards header to just "Dashboards" (ticket 007)

Drop the redundant profile-name suffix from the Dashboards section
header; the active profile is already surfaced via the profile
dropdown in NavMenu.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XFUNZwCvz3kcod3352ZR2o

webapp/src/components/Dashboards.tsx

@@ -253,7 +253,7 @@ export function Dashboards({ range }: { range: TimeRange | null }) {
         onKeyDown={handleSectionHeaderKeyDown(() => setCollapsed(!collapsed))}
       >
         <div className={sectionHeaderLeftClassName}>
-          Dashboards — profile "{activeProfile}"
+          Dashboards
           <HelpIcon sectionId="dashboards" label="Help: Dashboards" />
         </div>
         <div className="flex items-center gap-1.5">