feat: add styles and polish for unified session list components

- Add CSS styles for SessionCard and SessionList components
- Add responsive styles for mobile viewport
- Fix TypeScript errors (remove unused port property)
- Fix ESLint errors (remove unused imports and variables)

Refs: session-list-overhaul tasks 5-6

apps/web/src/pages/dashboard.tsx

@@ -11,7 +11,6 @@ import type { Project } from "../types";
 import { Icon } from "../components/icon";
 import { CreateSessionForm } from "../components/create-session-form";
 import { SessionList } from "../components/session-list";
-import { SessionCard } from "../components/session-card";
 
 type HomeStatus = "loading" | "ready" | "error";
 
@@ -125,11 +124,6 @@ export const HomePage = () => {
     [safeSessions]
   );
 
-  const recentSessions = useMemo(
-    () => safeSessions.filter((session) => ["stopped", "error"].includes(session.status)).slice(0, 5),
-    [safeSessions]
-  );
-
   const handleCreateSuccess = async (instance: { id: string }) => {
     await updateUserConfig({ last_session_id: instance.id });
     setSelectedProject("");