feat(cli): match TUI footer to reference design

- Remove borders from input bar — clean '❯ message mosaic…' prompt
- Two-line footer without borders:
  - Line 1: compact cwd (branch) | Gateway: Connected/Disconnected
  - Line 2: token stats (^in v_out R_cache W_cache $cost ctx%) | (provider) model
- Extend TokenUsage with cacheRead, cacheWrite, cost, contextPercent, contextWindow
- Add providerName to socket hook return
- Reorder layout: top bar → messages → input → footer

packages/cli/src/tui/app.tsx

@@ -47,13 +47,20 @@ export function TuiApp({ gatewayUrl, conversationId, sessionCookie }: TuiAppProp
         activeToolCalls={socket.activeToolCalls}
       />
 
-      <BottomBar gitInfo={gitInfo} tokenUsage={socket.tokenUsage} />
-
       <InputBar
         onSubmit={socket.sendMessage}
         isStreaming={socket.isStreaming}
         connected={socket.connected}
       />
+
+      <BottomBar
+        gitInfo={gitInfo}
+        tokenUsage={socket.tokenUsage}
+        connected={socket.connected}
+        connecting={socket.connecting}
+        modelName={socket.modelName}
+        providerName={socket.providerName}
+      />
     </Box>
   );
 }