feat(profile)!: replace sidebar and add avatar navigation

Rename the global Sidebar route, UI, assets, analytics, and payment return context to Profile. Add accessible message-avatar navigation and preserve the source character across auth and logout flows.

BREAKING CHANGE: /sidebar has been removed; use /profile instead.

src/app/chat/chat-screen.tsx

@@ -15,7 +15,9 @@ import {
 } from "@/providers/character-provider";
 import { useCharacterCatalog } from "@/providers/character-catalog-provider";
 import { clearPendingChatNavigation } from "@/lib/navigation/chat_unlock_session";
-import { getCharacterRoutes } from "@/router/routes";
+import { buildGlobalPageUrl } from "@/router/global-route-context";
+import { resolveAuthenticatedNavigation } from "@/router/navigation-resolver";
+import { getCharacterRoutes, ROUTES } from "@/router/routes";
 
 import { MobileShell } from "@/app/_components/core";
 
@@ -57,6 +59,10 @@ export function ChatScreen() {
   const refreshCharacterCatalog = characterCatalog.refresh;
   const defaultCharacterSlug = characterCatalog.defaultCharacter.slug;
   const characterRoutes = useActiveCharacterRoutes();
+  const profileUrl = buildGlobalPageUrl(
+    ROUTES.profile,
+    characterRoutes.chat,
+  );
   const searchParams = useSearchParams();
   const state = useChatState();
   const chatDispatch = useChatDispatch();
@@ -234,6 +240,19 @@ export function ChatScreen() {
     });
   }
 
+  function handleOpenUserProfile(): void {
+    router.push(
+      resolveAuthenticatedNavigation({
+        loginStatus: authState.loginStatus,
+        targetUrl: profileUrl,
+      }),
+    );
+  }
+
+  function handleOpenCharacterPrivateRoom(): void {
+    router.push(characterRoutes.privateRoom);
+  }
+
   return (
     <MobileShell>
       <div
@@ -280,6 +299,8 @@ export function ChatScreen() {
             onUnlockVoiceMessage={handleUnlockVoiceMessage}
             onUnlockImageMessage={handleUnlockImageMessage}
             onOpenImage={handleOpenImage}
+            onUserAvatarClick={handleOpenUserProfile}
+            onCharacterAvatarClick={handleOpenCharacterPrivateRoom}
             onLoadMoreHistory={() => {
               chatDispatch({ type: "ChatLoadMoreHistoryRequested" });
             }}