fix: thread safety for concurrent subagent delegation (#1672)

* fix: thread safety for concurrent subagent delegation

Four thread-safety fixes that prevent crashes and data races when
running multiple subagents concurrently via delegate_task:

1. Remove redirect_stdout/stderr from delegate_tool — mutating global
   sys.stdout races with the spinner thread when multiple children start
   concurrently, causing segfaults. Children already run with
   quiet_mode=True so the redirect was redundant.

2. Split _run_single_child into _build_child_agent (main thread) +
   _run_single_child (worker thread). AIAgent construction creates
   httpx/SSL clients which are not thread-safe to initialize
   concurrently.

3. Add threading.Lock to SessionDB — subagents share the parent's
   SessionDB and call create_session/append_message from worker threads
   with no synchronization.

4. Add _active_children_lock to AIAgent — interrupt() iterates
   _active_children while worker threads append/remove children.

5. Add _client_cache_lock to auxiliary_client — multiple subagent
   threads may resolve clients concurrently via call_llm().

Based on PR #1471 by peteromallet.

* feat: Honcho base_url override via config.yaml + quick command alias type

Two features salvaged from PR #1576:

1. Honcho base_url override: allows pointing Hermes at a remote
   self-hosted Honcho deployment via config.yaml:

     honcho:
       base_url: "http://192.168.x.x:8000"

   When set, this overrides the Honcho SDK's environment mapping
   (production/local), enabling LAN/VPN Honcho deployments without
   requiring the server to live on localhost. Uses config.yaml instead
   of env var (HONCHO_URL) per project convention.

2. Quick command alias type: adds a new 'alias' quick command type
   that rewrites to another slash command before normal dispatch:

     quick_commands:
       sc:
         type: alias
         target: /context

   Supports both CLI and gateway. Arguments are forwarded to the
   target command.

Based on PR #1576 by redhelix.

---------

Co-authored-by: peteromallet <peteromallet@users.noreply.github.com>
Co-authored-by: redhelix <redhelix@users.noreply.github.com>

cli.py

@@ -3652,8 +3652,17 @@ class HermesCLI:
                             self.console.print(f"[bold red]Quick command error: {e}[/]")
                     else:
                         self.console.print(f"[bold red]Quick command '{base_cmd}' has no command defined[/]")
+                elif qcmd.get("type") == "alias":
+                    target = qcmd.get("target", "").strip()
+                    if target:
+                        target = target if target.startswith("/") else f"/{target}"
+                        user_args = cmd_original[len(base_cmd):].strip()
+                        aliased_command = f"{target} {user_args}".strip()
+                        return self.process_command(aliased_command)
+                    else:
+                        self.console.print(f"[bold red]Quick command '{base_cmd}' has no target defined[/]")
                 else:
-                    self.console.print(f"[bold red]Quick command '{base_cmd}' has unsupported type (only 'exec' is supported)[/]")
+                    self.console.print(f"[bold red]Quick command '{base_cmd}' has unsupported type (supported: 'exec', 'alias')[/]")
             # Check for skill slash commands (/gif-search, /axolotl, etc.)
             elif base_cmd in _skill_commands:
                 user_instruction = cmd_original[len(base_cmd):].strip()