feat(terminal): switch terminal transport to pure websocket with fallback (#762)

* feat(terminal): add resumable websocket transport

Unify terminal input and stream traffic on `/api/terminal/ws` with a v2 control-frame protocol and advertised transport capabilities.

Buffer recent PTY output on the server so rebinding clients can replay missed chunks after reconnects or startup races, while keeping SSE as a fallback stream path.

Update the web terminal client and store to negotiate the new transport, track tab lifecycle, and avoid reopening exited sessions when restoring tabs.

* fix(terminal): retry rehydrated websocket reconnects

* fix(terminal): keep reconnect retries silent

* fix(terminal): wire ws stream output and replay in runtime

* fix(web): enable ws proxy for /api in dev

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/lib/api/types.ts

@@ -29,20 +29,23 @@ export interface RetryPolicy {
   maxDelayMs: number;
 }
 
+export interface TerminalTransportCapability {
+  preferred?: 'ws' | 'http' | 'sse';
+  transports?: Array<'ws' | 'http' | 'sse'>;
+  ws?: {
+    path: string;
+    v?: number;
+    enc?: string;
+  };
+}
+
 export interface TerminalSession {
   sessionId: string;
   cols: number;
   rows: number;
   capabilities?: {
-    input?: {
-      preferred?: 'ws' | 'http';
-      transports?: Array<'ws' | 'http'>;
-      ws?: {
-        path: string;
-        v?: number;
-        enc?: string;
-      };
-    };
+    input?: TerminalTransportCapability;
+    stream?: TerminalTransportCapability;
   };
 }