feat(cli): add langgraph deploy (#7004)

Allow users to deploy to langsmith deployments from the langgraph-cli.
This PR makes the following changes:
1. Add a simple host backend client with httpx
2. Adjust `progress.py` to show elapsed time for commands, and also use
threading.Event to stop the spinner
3. Adjust `_build` to allow arbitrary command so we can pass `docker
buildx build` and default to `docker build`
4. Add new `deploy` command, this re-uses a lot of the `langgraph build`
functionality, and then uses the new host-backend client to push the
built image to langsmith deployments.

---------

Co-authored-by: David Asamu <david.asamu@langchain.dev>

libs/cli/langgraph_cli/progress.py

@@ -12,8 +12,12 @@ class Progress:
         while True:
             yield from "|/-\\"
 
-    def __init__(self, *, message=""):
+    def __init__(self, *, message="", elapsed: bool = False):
         self.message = message
+        self._base_message = message
+        self._show_elapsed = elapsed
+        # use this to make sure we don't kill thread when we set msg to ""
+        self._stop = threading.Event()
         self.spinner_generator = self.spinning_cursor()
 
     def spinner_iteration(self):
@@ -29,9 +33,23 @@ class Progress:
         )
         sys.stdout.flush()
 
+    def _format_elapsed(self, seconds: float) -> str:
+        mins, secs = divmod(int(seconds), 60)
+        if mins:
+            return f"{self._base_message} ({mins}m {secs:02d}s)"
+        return f"{self._base_message} ({secs}s)"
+
     def spinner_task(self):
-        while self.message:
+        start = time.monotonic()
+        while not self._stop.is_set():
+            if not self.message:
+                time.sleep(self.delay)
+                continue
+            if self._show_elapsed:
+                self.message = self._format_elapsed(time.monotonic() - start)
             message = self.message
+            if not message:
+                continue
             sys.stdout.write(next(self.spinner_generator) + " " + message)
             sys.stdout.flush()
             time.sleep(self.delay)
@@ -50,21 +68,22 @@ class Progress:
 
             def set_message(message):
                 self.message = message
-                if not message:
-                    self.thread.join()
+                self._base_message = message or self._base_message
 
             return set_message
         else:
 
             def set_message(message):
-                sys.stderr.write(message + "\n")
-                sys.stderr.flush()
+                if message:
+                    sys.stderr.write(message + "\n")
+                    sys.stderr.flush()
 
             return set_message
 
     def __exit__(self, exception, value, tb):
         if sys.stdout.isatty():
             self.message = ""
+            self._stop.set()
             try:
                 self.thread.join()
             finally: