feat(update): enable passive upgrade nudge (opt out with VASTAI_NO_UPDATE_CHECK) (#439)

Author: sammy-vastai

docs/install-design.md

@@ -171,10 +171,9 @@ Not built in v1.
 
 ## 7. Passive update nudge
 
-> **Status: implemented but disabled.** The call is commented out in
-> `main.py` — updates are manual via `vastai update` for now. Re-enable the
-> two lines when we want the per-command check (the logic and tests below all
-> exist and pass).
+> **Status: enabled.** `notify_update(args)` runs as a post-command hook in
+> `main.py`. Opt out with `VASTAI_NO_UPDATE_CHECK=1` (also off under
+> `--raw`/`CI`/non-TTY).
 
 - After commands: at most **one manifest GET and one stderr line per 24h**, hard
   1s timeout, every failure silent with 24h backoff (offline machines pay ≤1s

vastai/cli/main.py

@@ -157,8 +157,11 @@ def quote_completions(self, completions: List[str], cword_prequote: str, last_wo
         try:
             res = args.func(args)
 
-            # Passive upgrade nudge — disabled for now (manual `vastai update`).
-            # from vastai.cli.selfupdate import notify_update; notify_update(args)
+            # Passive upgrade nudge: best-effort, ≤1 manifest GET + ≤1 stderr
+            # line per 24h, silent when offline/piped/CI. Never raises. Opt out
+            # with VASTAI_NO_UPDATE_CHECK=1. See selfupdate.py and §7.
+            from vastai.cli.selfupdate import notify_update
+            notify_update(args)
 
             if args.raw and res is not None:
                 try: