fix(gateway): wire -v/-q flags to stderr logging

By default 'hermes gateway run' now prints WARNING+ to stderr so
connection errors and startup failures are visible in the terminal
without having to tail ~/.hermes/logs/gateway.log.

- gateway/run.py: start_gateway() accepts verbosity: Optional[int]=0.
  When not None, attaches a StreamHandler to stderr with level mapped
  from the count (0=WARNING, 1=INFO, 2+=DEBUG). Root logger level is
  also lowered when DEBUG is requested so records are not swallowed.

- hermes_cli/gateway.py: run_gateway() gains verbose: int and
  quiet: bool params. -q translates to verbosity=None (no stderr
  handler). Wired through gateway_command().

- hermes_cli/main.py: -v changed from store_true to action=count so
  -v/-vv/-vvv each increment the level. -q/--quiet added as a new flag.

Behaviour summary:
  hermes gateway run        -> WARNING+ on stderr (default)
  hermes gateway run -q     -> silent
  hermes gateway run -v     -> INFO+
  hermes gateway run -vv    -> DEBUG

hermes_cli/main.py

@@ -3857,7 +3857,10 @@ For more help on a command:
     
     # gateway run (default)
     gateway_run = gateway_subparsers.add_parser("run", help="Run gateway in foreground")
-    gateway_run.add_argument("-v", "--verbose", action="store_true")
+    gateway_run.add_argument("-v", "--verbose", action="count", default=0,
+                             help="Increase stderr log verbosity (-v=INFO, -vv=DEBUG)")
+    gateway_run.add_argument("-q", "--quiet", action="store_true",
+                             help="Suppress all stderr log output")
     gateway_run.add_argument("--replace", action="store_true",
                              help="Replace any existing gateway instance (useful for systemd)")