Enhance logging and timing in CLI and session operations

- Updated the `_print_checks` function to replace console prints with logging functions for better traceability.
- Introduced timing functionality in the `doctor`, `dry_run`, and `up` functions to log the duration of preflight checks.
- Modified the `wait_ssh` function to accept a logging callback, improving SSH wait feedback.
- Enhanced the `mark` method in `PhaseTimes` to log phase durations, aiding in performance analysis.
- Updated various remote scripts to ensure error messages are printed to stderr for better error handling.

src/gpu_rent/remote/swarmui_set_api_keys.py

@@ -53,7 +53,7 @@ def main() -> int:
     try:
         raw = json.loads(KEYS_PATH.read_text(encoding="utf-8"))
     except (OSError, json.JSONDecodeError) as exc:
-        print(f"bad keys file: {exc}", file=sys.stderr)
+        print(f"bad keys file: {exc}")
         return 1
     finally:
         try:
@@ -74,13 +74,13 @@ def main() -> int:
                 {"session_id": sid, "keyType": key_type, "key": value},
             )
         except (urllib.error.URLError, urllib.error.HTTPError, TimeoutError, OSError, json.JSONDecodeError) as exc:
-            print(f"SetAPIKey {key_type} failed: {exc}", file=sys.stderr)
+            print(f"SetAPIKey {key_type} failed: {exc}")
             return 1
         if resp.get("error"):
-            print(f"SetAPIKey {key_type}: {resp['error']}", file=sys.stderr)
+            print(f"SetAPIKey {key_type}: {resp['error']}")
             return 1
         if not resp.get("success"):
-            print(f"SetAPIKey {key_type}: unexpected {resp}", file=sys.stderr)
+            print(f"SetAPIKey {key_type}: unexpected {resp}")
             return 1
         print(f"SetAPIKey {key_type}=ok")
     return 0