feat(types): CommandDef, CommandManifest, slash command socket events

- Add CommandDef, CommandArgDef, CommandManifest, SkillCommandDef types
- Add slash command payload types (SlashCommandPayload, SlashCommandResultPayload)
- Add SystemReloadPayload and CommandManifestPayload
- Add ParsedCommand type for TUI-side parsing
- Wire new events into ServerToClientEvents and ClientToServerEvents

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

packages/types/src/chat/events.ts

@@ -1,3 +1,10 @@
+import type {
+  CommandManifestPayload,
+  SlashCommandPayload,
+  SlashCommandResultPayload,
+  SystemReloadPayload,
+} from '../commands/index.js';
+
 export interface MessageAckPayload {
   conversationId: string;
   messageId: string;
@@ -92,6 +99,9 @@ export interface ServerToClientEvents {
   'agent:tool:start': (payload: ToolStartPayload) => void;
   'agent:tool:end': (payload: ToolEndPayload) => void;
   'session:info': (payload: SessionInfoPayload) => void;
+  'commands:manifest': (payload: CommandManifestPayload) => void;
+  'command:result': (payload: SlashCommandResultPayload) => void;
+  'system:reload': (payload: SystemReloadPayload) => void;
   error: (payload: ErrorPayload) => void;
 }
 
@@ -99,4 +109,5 @@ export interface ServerToClientEvents {
 export interface ClientToServerEvents {
   message: (data: ChatMessagePayload) => void;
   'set:thinking': (data: SetThinkingPayload) => void;
+  'command:execute': (data: SlashCommandPayload) => void;
 }

packages/types/src/commands/index.ts

@@ -0,0 +1,85 @@
+/** Argument definition for a slash command */
+export interface CommandArgDef {
+  name: string;
+  type: 'string' | 'enum';
+  optional: boolean;
+  /** For enum type, the allowed values */
+  values?: string[];
+  description?: string;
+}
+
+/** A single command definition served by the gateway */
+export interface CommandDef {
+  /** Command name without slash prefix, e.g. "model" */
+  name: string;
+  /** Short aliases, e.g. ["m"] */
+  aliases: string[];
+  /** Human-readable description */
+  description: string;
+  /** Argument schema */
+  args?: CommandArgDef[];
+  /** Nested subcommands (e.g. provider → login, logout) */
+  subcommands?: CommandDef[];
+  /** Origin of this command */
+  scope: 'core' | 'agent' | 'skill' | 'plugin' | 'admin';
+  /** Where the command executes */
+  execution: 'local' | 'socket' | 'rest' | 'hybrid';
+  /** Whether this command is currently available */
+  available: boolean;
+}
+
+/** Full command manifest pushed from gateway to TUI */
+export interface CommandManifest {
+  commands: CommandDef[];
+  skills: SkillCommandDef[];
+  /** Manifest version — TUI compares to detect changes */
+  version: number;
+}
+
+/** Skill registered as /skill:name */
+export interface SkillCommandDef {
+  /** Skill name (used as /skill:{name}) */
+  name: string;
+  description: string;
+  /** Whether the skill is currently loaded and available */
+  available: boolean;
+}
+
+/** Payload for commands:manifest event */
+export interface CommandManifestPayload {
+  manifest: CommandManifest;
+}
+
+/** Payload for system:reload broadcast */
+export interface SystemReloadPayload {
+  commands: CommandDef[];
+  skills: SkillCommandDef[];
+  providers: string[];
+  message: string;
+}
+
+/** Client request to execute a slash command via socket */
+export interface SlashCommandPayload {
+  conversationId: string;
+  command: string;
+  args?: string;
+}
+
+/** Server response to a slash command */
+export interface SlashCommandResultPayload {
+  conversationId: string;
+  command: string;
+  success: boolean;
+  message?: string;
+  data?: Record<string, unknown>;
+}
+
+/** Parsed slash command (TUI-side, not a socket type) */
+export interface ParsedCommand {
+  /** Command name without slash, e.g. "model", "skill:brave-search" */
+  command: string;
+  /** Arguments string or null */
+  args: string | null;
+  /** Full raw input string */
+  raw: string;
+}

packages/types/src/index.ts

@@ -4,3 +4,4 @@ export * from './chat/index.js';
 export * from './agent/index.js';
 export * from './provider/index.js';
 export * from './routing/index.js';
+export * from './commands/index.js';