feat(gateway): expose plugin slash commands natively on all platforms + decision-capable command hook

Plugin slash commands now surface as first-class commands in every gateway
enumerator — Discord native slash picker, Telegram BotCommand menu, Slack
/hermes subcommand map — without a separate per-platform plugin API.

The existing 'command:<name>' gateway hook gains a decision protocol via
HookRegistry.emit_collect(): handlers that return a dict with
{'decision': 'deny'|'handled'|'rewrite'|'allow'} can intercept slash
command dispatch before core handling runs, unifying what would otherwise
have been a parallel 'pre_gateway_command' hook surface.

Changes:

- gateway/hooks.py: add HookRegistry.emit_collect() that fires the same
  handler set as emit() but collects non-None return values. Backward
  compatible — fire-and-forget telemetry hooks still work via emit().
- hermes_cli/plugins.py: add optional 'args_hint' param to
  register_command() so plugins can opt into argument-aware native UI
  registration (Discord arg picker, future platforms).
- hermes_cli/commands.py: add _iter_plugin_command_entries() helper and
  merge plugin commands into telegram_bot_commands() and
  slack_subcommand_map(). New is_gateway_known_command() recognizes both
  built-in and plugin commands so the gateway hook fires for either.
- gateway/platforms/discord.py: extract _build_auto_slash_command helper
  from the COMMAND_REGISTRY auto-register loop and reuse it for
  plugin-registered commands. Built-in name conflicts are skipped.
- gateway/run.py: before normal slash dispatch, call emit_collect on
  command:<canonical> and honor deny/handled/rewrite/allow decisions.
  Hook now fires for plugin commands too.
- scripts/release.py: AUTHOR_MAP entry for @Magaav.
- Tests: emit_collect semantics, plugin command surfacing per platform,
  decision protocol (deny/handled/rewrite/allow + non-dict tolerance),
  Discord plugin auto-registration + conflict skipping, is_gateway_known_command.

Salvaged from #14131 (@Magaav). Original PR added a parallel
'pre_gateway_command' hook and a platform-keyed plugin command
registry; this re-implementation reuses the existing 'command:<name>'
hook and treats plugin commands as platform-agnostic so the same
capability reaches Telegram and Slack without new API surface.

Co-authored-by: Magaav <73175452+Magaav@users.noreply.github.com>

gateway/hooks.py

@@ -135,9 +135,22 @@ class HookRegistry:
             except Exception as e:
                 print(f"[hooks] Error loading hook {hook_dir.name}: {e}", flush=True)
 
+    def _resolve_handlers(self, event_type: str) -> List[Callable]:
+        """Return all handlers that should fire for ``event_type``.
+
+        Exact matches fire first, followed by wildcard matches (e.g.
+        ``command:*`` matches ``command:reset``).
+        """
+        handlers = list(self._handlers.get(event_type, []))
+        if ":" in event_type:
+            base = event_type.split(":")[0]
+            wildcard_key = f"{base}:*"
+            handlers.extend(self._handlers.get(wildcard_key, []))
+        return handlers
+
     async def emit(self, event_type: str, context: Optional[Dict[str, Any]] = None) -> None:
         """
-        Fire all handlers registered for an event.
+        Fire all handlers registered for an event, discarding return values.
 
         Supports wildcard matching: handlers registered for "command:*" will
         fire for any "command:..." event. Handlers registered for a base type
@@ -151,16 +164,7 @@ class HookRegistry:
         if context is None:
             context = {}
 
-        # Collect handlers: exact match + wildcard match
-        handlers = list(self._handlers.get(event_type, []))
-
-        # Check for wildcard patterns (e.g., "command:*" matches "command:reset")
-        if ":" in event_type:
-            base = event_type.split(":")[0]
-            wildcard_key = f"{base}:*"
-            handlers.extend(self._handlers.get(wildcard_key, []))
-
-        for fn in handlers:
+        for fn in self._resolve_handlers(event_type):
             try:
                 result = fn(event_type, context)
                 # Support both sync and async handlers
@@ -168,3 +172,32 @@ class HookRegistry:
                     await result
             except Exception as e:
                 print(f"[hooks] Error in handler for '{event_type}': {e}", flush=True)
+
+    async def emit_collect(
+        self,
+        event_type: str,
+        context: Optional[Dict[str, Any]] = None,
+    ) -> List[Any]:
+        """Fire handlers and return their non-None return values in order.
+
+        Like :meth:`emit` but captures each handler's return value. Used for
+        decision-style hooks (e.g. ``command:<name>`` policies that want to
+        allow/deny/rewrite the command before normal dispatch).
+
+        Exceptions from individual handlers are logged but do not abort the
+        remaining handlers.
+        """
+        if context is None:
+            context = {}
+
+        results: List[Any] = []
+        for fn in self._resolve_handlers(event_type):
+            try:
+                result = fn(event_type, context)
+                if asyncio.iscoroutine(result):
+                    result = await result
+                if result is not None:
+                    results.append(result)
+            except Exception as e:
+                print(f"[hooks] Error in handler for '{event_type}': {e}", flush=True)
+        return results

gateway/platforms/discord.py

@@ -2129,10 +2129,42 @@ class DiscordAdapter(BasePlatformAdapter):
         # This ensures new commands added to COMMAND_REGISTRY in
         # hermes_cli/commands.py automatically appear as Discord slash
         # commands without needing a manual entry here.
+        def _build_auto_slash_command(_name: str, _description: str, _args_hint: str = ""):
+            """Build a discord.app_commands.Command that proxies to _run_simple_slash."""
+            discord_name = _name.lower()[:32]
+            desc = (_description or f"Run /{_name}")[:100]
+            has_args = bool(_args_hint)
+
+            if has_args:
+                def _make_args_handler(__name: str, __hint: str):
+                    @discord.app_commands.describe(args=f"Arguments: {__hint}"[:100])
+                    async def _handler(interaction: discord.Interaction, args: str = ""):
+                        await self._run_simple_slash(
+                            interaction, f"/{__name} {args}".strip()
+                        )
+                    _handler.__name__ = f"auto_slash_{__name.replace('-', '_')}"
+                    return _handler
+
+                handler = _make_args_handler(_name, _args_hint)
+            else:
+                def _make_simple_handler(__name: str):
+                    async def _handler(interaction: discord.Interaction):
+                        await self._run_simple_slash(interaction, f"/{__name}")
+                    _handler.__name__ = f"auto_slash_{__name.replace('-', '_')}"
+                    return _handler
+
+                handler = _make_simple_handler(_name)
+
+            return discord.app_commands.Command(
+                name=discord_name,
+                description=desc,
+                callback=handler,
+            )
+
+        already_registered: set[str] = set()
         try:
             from hermes_cli.commands import COMMAND_REGISTRY, _is_gateway_available, _resolve_config_gates
 
-            already_registered = set()
             try:
                 already_registered = {cmd.name for cmd in tree.get_commands()}
             except Exception:
@@ -2147,38 +2179,10 @@ class DiscordAdapter(BasePlatformAdapter):
                 discord_name = cmd_def.name.lower()[:32]
                 if discord_name in already_registered:
                     continue
-                # Skip aliases that overlap with already-registered names
-                # (aliases for explicitly registered commands are handled above).
-                desc = (cmd_def.description or f"Run /{cmd_def.name}")[:100]
-                has_args = bool(cmd_def.args_hint)
-
-                if has_args:
-                    # Command takes optional arguments — create handler with
-                    # an optional ``args`` string parameter.
-                    def _make_args_handler(_name: str, _hint: str):
-                        @discord.app_commands.describe(args=f"Arguments: {_hint}"[:100])
-                        async def _handler(interaction: discord.Interaction, args: str = ""):
-                            await self._run_simple_slash(
-                                interaction, f"/{_name} {args}".strip()
-                            )
-                        _handler.__name__ = f"auto_slash_{_name.replace('-', '_')}"
-                        return _handler
-
-                    handler = _make_args_handler(cmd_def.name, cmd_def.args_hint)
-                else:
-                    # Parameterless command.
-                    def _make_simple_handler(_name: str):
-                        async def _handler(interaction: discord.Interaction):
-                            await self._run_simple_slash(interaction, f"/{_name}")
-                        _handler.__name__ = f"auto_slash_{_name.replace('-', '_')}"
-                        return _handler
-
-                    handler = _make_simple_handler(cmd_def.name)
-
-                auto_cmd = discord.app_commands.Command(
-                    name=discord_name,
-                    description=desc,
-                    callback=handler,
+                auto_cmd = _build_auto_slash_command(
+                    cmd_def.name,
+                    cmd_def.description,
+                    cmd_def.args_hint,
                 )
                 try:
                     tree.add_command(auto_cmd)
@@ -2195,6 +2199,35 @@ class DiscordAdapter(BasePlatformAdapter):
         except Exception as e:
             logger.warning("Discord auto-register from COMMAND_REGISTRY failed: %s", e)
 
+        # ── Plugin-registered slash commands ──
+        # Plugins register via PluginContext.register_command(); we mirror
+        # those into Discord's native slash picker so users get the same
+        # autocomplete UX as for built-in commands. No per-platform plugin
+        # API needed — plugin commands are platform-agnostic.
+        try:
+            from hermes_cli.commands import _iter_plugin_command_entries
+
+            for plugin_name, plugin_desc, plugin_args_hint in _iter_plugin_command_entries():
+                discord_name = plugin_name.lower()[:32]
+                if discord_name in already_registered:
+                    continue
+                auto_cmd = _build_auto_slash_command(
+                    plugin_name,
+                    plugin_desc,
+                    plugin_args_hint,
+                )
+                try:
+                    tree.add_command(auto_cmd)
+                    already_registered.add(discord_name)
+                except Exception:
+                    # Silently skip commands that fail registration (e.g.
+                    # name conflict with a subcommand group).
+                    pass
+        except Exception as e:
+            logger.warning(
+                "Discord auto-register from plugin commands failed: %s", e
+            )
+
         # Register skills under a single /skill command group with category
         # subcommand groups.  This uses 1 top-level slot instead of N,
         # supporting up to 25 categories × 25 skills = 625 skills.

gateway/run.py

@@ -3485,23 +3485,73 @@ class GatewayRunner:
 
         # Check for commands
         command = event.get_command()
-        
-        # Emit command:* hook for any recognized slash command.
-        # GATEWAY_KNOWN_COMMANDS is derived from the central COMMAND_REGISTRY
-        # in hermes_cli/commands.py — no hardcoded set to maintain here.
-        from hermes_cli.commands import GATEWAY_KNOWN_COMMANDS, resolve_command as _resolve_cmd
-        if command and command in GATEWAY_KNOWN_COMMANDS:
-            await self.hooks.emit(f"command:{command}", {
-                "platform": source.platform.value if source.platform else "",
-                "user_id": source.user_id,
-                "command": command,
-                "args": event.get_command_args().strip(),
-            })
 
-        # Resolve aliases to canonical name so dispatch only checks canonicals.
+        from hermes_cli.commands import (
+            GATEWAY_KNOWN_COMMANDS,
+            is_gateway_known_command,
+            resolve_command as _resolve_cmd,
+        )
+
+        # Resolve aliases to canonical name so dispatch and hook names
+        # don't depend on the exact alias the user typed.
         _cmd_def = _resolve_cmd(command) if command else None
         canonical = _cmd_def.name if _cmd_def else command
 
+        # Fire the ``command:<canonical>`` hook for any recognized slash
+        # command — built-in OR plugin-registered. Handlers can return a
+        # dict with ``{"decision": "deny" | "handled" | "rewrite", ...}``
+        # to intercept dispatch before core handling runs. This replaces
+        # the previous fire-and-forget emit(): return values are now
+        # honored, but handlers that return nothing behave exactly as
+        # before (telemetry-style hooks keep working).
+        if command and is_gateway_known_command(canonical):
+            raw_args = event.get_command_args().strip()
+            hook_ctx = {
+                "platform": source.platform.value if source.platform else "",
+                "user_id": source.user_id,
+                "command": canonical,
+                "raw_command": command,
+                "args": raw_args,
+                "raw_args": raw_args,
+            }
+            try:
+                hook_results = await self.hooks.emit_collect(
+                    f"command:{canonical}", hook_ctx
+                )
+            except Exception as _hook_err:
+                logger.debug(
+                    "command:%s hook dispatch failed (non-fatal): %s",
+                    canonical, _hook_err,
+                )
+                hook_results = []
+
+            for hook_result in hook_results:
+                if not isinstance(hook_result, dict):
+                    continue
+                decision = str(hook_result.get("decision", "")).strip().lower()
+                if not decision or decision == "allow":
+                    continue
+                if decision == "deny":
+                    message = hook_result.get("message")
+                    if isinstance(message, str) and message:
+                        return message
+                    return f"Command `/{command}` was blocked by a hook."
+                if decision == "handled":
+                    message = hook_result.get("message")
+                    return message if isinstance(message, str) and message else None
+                if decision == "rewrite":
+                    new_command = str(
+                        hook_result.get("command_name", "")
+                    ).strip().lstrip("/")
+                    if not new_command:
+                        continue
+                    new_args = str(hook_result.get("raw_args", "")).strip()
+                    event.text = f"/{new_command} {new_args}".strip()
+                    command = event.get_command()
+                    _cmd_def = _resolve_cmd(command) if command else None
+                    canonical = _cmd_def.name if _cmd_def else command
+                    break
+
         if canonical == "new":
             return await self._handle_reset_command(event)