fix(deploy-progress): decouple deploys from the live progress stream (#1246)

* fix(deploy-progress): decouple deploys from the live progress stream

The deploy progress modal streamed compose output over a WebSocket, but
the deploy itself was coupled to that socket in two ways that could break
or silently abort a deploy:

- The deploy request was gated on the progress socket connecting, so any
  upgrade failure (a reverse proxy blocking WebSocket upgrades, or the
  admin-only stream rejecting a scoped deployer) left the modal stuck on
  "Connecting..." and the deploy never fired.
- The backend terminated the running compose process when that socket
  closed, so minimizing the modal, navigating away, or a network blip
  aborted an in-flight deploy.

Make the progress socket output-only: the deploy is owned by its request
and runs to completion (or the existing command timeout) regardless of
the stream. The modal now degrades to a "Live progress unavailable" state
and still reports success or failure from the request result. Connect
failures, drops, and a connect timeout all release the deploy instead of
blocking it.

Also route progress output per deploy: the frontend sends a correlation
id on both the connectTerminal message and the deploy request header, and
the backend keys progress sockets by that id so concurrent deploys from
different tabs or users no longer cross-stream each other's output.

Cap the in-memory parsed log rows so a very long deploy cannot grow the
modal's state unbounded.

* fix(deploy-progress): generate the deploy session id with a CSPRNG

The per-deploy correlation id keys which WebSocket receives a deploy's
live output, so a guessable id lets one authenticated client register a
victim's id and read its compose output. It was built from Math.random()
plus a timestamp, which is not cryptographically secure.

Generate it with crypto.getRandomValues (128 bits, hex). That is the one
Crypto member available in insecure contexts, so it still works over LAN
HTTP where crypto.randomUUID is unavailable.

* fix(deploy-progress): stop headerless ops bleeding into a keyed progress modal

Address review findings on the progress-stream routing:

- Only an id-less connectTerminal registration may become the id-less
  fallback socket. Previously every connectTerminal (including keyed deploy
  modals) set the fallback, so a headerless operation (bulk update, rollback,
  or a legacy client) resolved via getTerminalWs() into another user's keyed
  deploy modal. Keyed sockets are now excluded from the fallback, and a socket
  that adopts a session id is removed from it.
- The connect-timeout fallback now also flags the modal as "Live progress
  unavailable" instead of leaving it on "Connecting..." while the deploy runs.
- Log only a short prefix of the deploy session id in developer diagnostics,
  not the full capability value.

backend/src/websocket/generic.ts

@@ -8,19 +8,28 @@ import { isDebugEnabled } from '../utils/debug';
 import { rejectUpgrade as reject } from './reject';
 
 /**
- * Module-scope singleton: the most recent WebSocket to send
- * `{action: 'connectTerminal'}` receives streaming output from any subsequent
- * compose deploy/down/update. Routes that want to echo compose progress read
- * the current value via `getTerminalWs()`.
- *
- * Intentionally single-instance. If multiple clients connect, the last one
- * wins. This matches pre-refactor behavior; race-hardening is a separate
- * concern.
+ * Header the deploy/update/down routes carry the per-deploy correlation id on,
+ * mirroring the `sessionId` the frontend sends in `{action:'connectTerminal'}`.
+ * Must stay in sync with `DEPLOY_SESSION_HEADER` in `frontend/src/lib/api.ts`.
  */
-let terminalWs: WebSocket | undefined;
+export const DEPLOY_SESSION_HEADER = 'x-deploy-session-id';
 
-export function getTerminalWs(): WebSocket | undefined {
-  return terminalWs;
+/**
+ * Registry of compose-progress sockets keyed by the per-deploy correlation id
+ * the frontend sends on `{action:'connectTerminal', sessionId}` and echoes on
+ * the deploy/update/down POST via {@link DEPLOY_SESSION_HEADER}. A route resolves
+ * the socket for its own deploy with `getTerminalWs(sessionId)`, so concurrent
+ * deploys from different tabs or users never cross-stream output to each other.
+ *
+ * `lastTerminalWs` is the fallback for callers that connect or stream without a
+ * session id (bulk operations, legacy clients): the most recent such socket wins.
+ */
+const terminalRegistry = new Map<string, WebSocket>();
+let lastTerminalWs: WebSocket | undefined;
+
+export function getTerminalWs(sessionId?: string): WebSocket | undefined {
+  const ws = sessionId ? terminalRegistry.get(sessionId) : lastTerminalWs;
+  return ws && ws.readyState === WebSocket.OPEN ? ws : undefined;
 }
 
 interface GenericContext {
@@ -85,6 +94,7 @@ export function handleGenericWs(
 export function attachGenericConnectionHandlers(wss: WebSocketServer): void {
   wss.on('connection', (ws) => {
     console.log('WebSocket connected');
+    let registeredSessionId: string | undefined;
 
     ws.on('message', (message) => {
       try {
@@ -92,7 +102,24 @@ export function attachGenericConnectionHandlers(wss: WebSocketServer): void {
         if (!data.action) return;
 
         if (data.action === 'connectTerminal') {
-          terminalWs = ws;
+          const sessionId = typeof data.sessionId === 'string' && data.sessionId ? data.sessionId : undefined;
+          // Rebind this socket to the new id, dropping any prior mapping it held.
+          if (registeredSessionId && registeredSessionId !== sessionId && terminalRegistry.get(registeredSessionId) === ws) {
+            terminalRegistry.delete(registeredSessionId);
+          }
+          registeredSessionId = sessionId;
+          if (sessionId) {
+            terminalRegistry.set(sessionId, ws);
+            // A keyed socket must never be the id-less fallback, or a headerless
+            // operation (bulk / rollback / legacy) would stream into this user's
+            // keyed deploy modal.
+            if (lastTerminalWs === ws) lastTerminalWs = undefined;
+          } else {
+            lastTerminalWs = ws;
+          }
+          if (isDebugEnabled()) {
+            console.debug('[Deploy:diag] progress stream registered', { session: sessionId ? `${sessionId.slice(0, 8)}…` : '(none)' });
+          }
         } else if (data.action === 'streamStats') {
           const requestedId = data.nodeId ? parseInt(data.nodeId, 10) : NodeRegistry.getInstance().getDefaultNodeId();
           // When a WS is proxied from a gateway to this remote instance, the
@@ -117,5 +144,12 @@ export function attachGenericConnectionHandlers(wss: WebSocketServer): void {
         // Malformed JSON - ignore silently
       }
     });
+
+    ws.on('close', () => {
+      if (registeredSessionId && terminalRegistry.get(registeredSessionId) === ws) {
+        terminalRegistry.delete(registeredSessionId);
+      }
+      if (lastTerminalWs === ws) lastTerminalWs = undefined;
+    });
   });
 }