fix(gateway): slash commands never interrupt a running agent (#12334)

Any recognized slash command now bypasses the Level-1 active-session
guard instead of queueing + interrupting. A mid-run /model (or
/reasoning, /voice, /insights, /title, /resume, /retry, /undo,
/compress, /usage, /provider, /reload-mcp, /sethome, /reset) used to
interrupt the agent AND get silently discarded by the slash-command
safety net — zero-char response, dropped tool calls.

Root cause:
- Discord registers 41 native slash commands via tree.command().
- Only 14 were in ACTIVE_SESSION_BYPASS_COMMANDS.
- The other ~15 user-facing ones fell through base.py:handle_message
  to the busy-session handler, which calls running_agent.interrupt()
  AND queues the text.
- After the aborted run, gateway/run.py:9912 correctly identifies the
  queued text as a slash command and discards it — but the damage
  (interrupt + zero-char response) already happened.

Fix:
- should_bypass_active_session() now returns True for any resolvable
  slash command. ACTIVE_SESSION_BYPASS_COMMANDS stays as the subset
  with dedicated Level-2 handlers (documentation + tests).
- gateway/run.py adds a catch-all after the dedicated handlers that
  returns a user-visible "agent busy — wait or /stop first" response
  for any other resolvable command.
- Unknown text / file-path-like messages are unchanged — they still
  queue.

Also:
- gateway/platforms/discord.py logs the invoker identity on every
  slash command (user id + name + channel + guild) so future
  ghost-command reports can be triaged without guessing.

Tests:
- 15 new parametrized cases in test_command_bypass_active_session.py
  cover every previously-broken Discord slash command.
- Existing tests for /stop, /new, /approve, /deny, /help, /status,
  /agents, /background, /steer, /update, /queue still pass.
- test_steer.py's ACTIVE_SESSION_BYPASS_COMMANDS check still passes.

Fixes #5057. Related: #6252, #10370, #4665.

gateway/platforms/discord.py

@@ -1933,6 +1933,24 @@ class DiscordAdapter(BasePlatformAdapter):
         the "thinking..." indicator is replaced with that text; otherwise it
         is deleted so the channel isn't cluttered.
         """
+        # Log the invoker so ghost-command reports can be triaged.  Discord
+        # native slash invocations are always user-initiated (no bot can fire
+        # them), but mobile autocomplete / keyboard shortcuts / other users
+        # in the same channel are easy to miss in post-mortems.
+        try:
+            _user = interaction.user
+            _chan_id = getattr(interaction.channel, "id", None) or getattr(interaction, "channel_id", None)
+            logger.info(
+                "[Discord] slash '%s' invoked by user=%s id=%s channel=%s guild=%s",
+                command_text,
+                getattr(_user, "name", "?"),
+                getattr(_user, "id", "?"),
+                _chan_id,
+                getattr(interaction, "guild_id", None),
+            )
+        except Exception:
+            pass  # logging must never block command dispatch
+
         await interaction.response.defer(ephemeral=True)
         event = self._build_slash_event(interaction, command_text)
         await self.handle_message(event)

gateway/run.py

@@ -2987,8 +2987,8 @@ class GatewayRunner:
 
             # Resolve the command once for all early-intercept checks below.
             from hermes_cli.commands import (
+                ACTIVE_SESSION_BYPASS_COMMANDS as _DEDICATED_HANDLERS,
                 resolve_command as _resolve_cmd_inner,
-                should_bypass_active_session as _should_bypass_active_inner,
             )
             _evt_cmd = event.get_command()
             _cmd_def_inner = _resolve_cmd_inner(_evt_cmd) if _evt_cmd else None
@@ -3123,11 +3123,9 @@ class GatewayRunner:
             if _cmd_def_inner and _cmd_def_inner.name == "background":
                 return await self._handle_background_command(event)
 
-            # Gateway-handled info/control commands must never fall through to
-            # the interrupt path. If they are queued as pending text, the
-            # slash-command safety net discards them before the user sees any
-            # response.
-            if _cmd_def_inner and _should_bypass_active_inner(_cmd_def_inner.name):
+            # Gateway-handled info/control commands with dedicated
+            # running-agent handlers.
+            if _cmd_def_inner and _cmd_def_inner.name in _DEDICATED_HANDLERS:
                 if _cmd_def_inner.name == "help":
                     return await self._handle_help_command(event)
                 if _cmd_def_inner.name == "commands":
@@ -3137,6 +3135,21 @@ class GatewayRunner:
                 if _cmd_def_inner.name == "update":
                     return await self._handle_update_command(event)
 
+            # Catch-all: any other recognized slash command reached the
+            # running-agent guard. Reject gracefully rather than falling
+            # through to interrupt + discard. Without this, commands
+            # like /model, /reasoning, /voice, /insights, /title,
+            # /resume, /retry, /undo, /compress, /usage, /provider,
+            # /reload-mcp, /sethome, /reset (all registered as Discord
+            # slash commands) would interrupt the agent AND get
+            # silently discarded by the slash-command safety net,
+            # producing a zero-char response. See #5057, #6252, #10370.
+            if _cmd_def_inner:
+                return (
+                    f"⏳ Agent is running — `/{_cmd_def_inner.name}` can't run "
+                    f"mid-turn. Wait for the current response or `/stop` first."
+                )
+
             if event.message_type == MessageType.PHOTO:
                 logger.debug("PRIORITY photo follow-up for session %s — queueing without interrupt", _quick_key[:20])
                 adapter = self.adapters.get(source.platform)