fix: cockpit/flowpilot bugs and redesign view toggle placement

- Fix return type annotation on unified_chat_service.send_chat_message (6→7 tuple)
- Fix stale closure in CockpitPage handleStepComplete auto-advance logic
- Fix IncidentHeader copy link hardcoding /assistant/ path (now uses current URL)
- Wire psaTicketId from session data through to CockpitPage incident header
- Fix FlowPilotAsks showing only first question — add chevron navigation for all
- Redesign ViewToggle: add icons (MessageSquare/LayoutDashboard) and subtitles
- Move view toggle from chatbar toolbar to standalone row above input on dashboard
- Standardize toggle placement across dashboard, FlowPilot, and Cockpit pages

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/pages/FlowPilotPage.tsx

@@ -116,7 +116,7 @@ export default function FlowPilotPage() {
                 </button>
                 <div className="flex-1" />
                 {session.activeChatId && (
-                  <ViewToggle currentView="flowpilot" sessionId={session.activeChatId} />
+                  <ViewToggle currentView="flowpilot" sessionId={session.activeChatId} showSubtitle={false} />
                 )}
                 <button
                   onClick={session.handleNewChat}