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/hooks/use-socket.ts

@@ -28,6 +28,11 @@ export interface TokenUsage {
   input: number;
   output: number;
   total: number;
+  cacheRead: number;
+  cacheWrite: number;
+  cost: number;
+  contextPercent: number;
+  contextWindow: number;
 }
 
 export interface UseSocketOptions {
@@ -47,6 +52,7 @@ export interface UseSocketReturn {
   activeToolCalls: ToolCall[];
   tokenUsage: TokenUsage;
   modelName: string | null;
+  providerName: string | null;
   sendMessage: (content: string) => void;
   connectionError: string | null;
 }
@@ -65,8 +71,18 @@ export function useSocket(opts: UseSocketOptions): UseSocketReturn {
   const [currentThinkingText, setCurrentThinkingText] = useState('');
   const [activeToolCalls, setActiveToolCalls] = useState<ToolCall[]>([]);
   // TODO: wire up once gateway emits token-usage and model-info events
-  const tokenUsage: TokenUsage = { input: 0, output: 0, total: 0 };
+  const tokenUsage: TokenUsage = {
+    input: 0,
+    output: 0,
+    total: 0,
+    cacheRead: 0,
+    cacheWrite: 0,
+    cost: 0,
+    contextPercent: 0,
+    contextWindow: 0,
+  };
   const modelName: string | null = null;
+  const providerName: string | null = null;
   const [connectionError, setConnectionError] = useState<string | null>(null);
 
   const socketRef = useRef<TypedSocket | null>(null);
@@ -191,6 +207,7 @@ export function useSocket(opts: UseSocketOptions): UseSocketReturn {
     activeToolCalls,
     tokenUsage,
     modelName,
+    providerName,
     sendMessage,
     connectionError,
   };