feat(commands): Implement argument handling for custom commands via a prompt pipeline (#4702)

packages/cli/src/ui/commands/types.ts

@@ -14,6 +14,15 @@ import { SessionStatsState } from '../contexts/SessionContext.js';
 
 // Grouped dependencies for clarity and easier mocking
 export interface CommandContext {
+  // Invocation properties for when commands are called.
+  invocation?: {
+    /** The raw, untrimmed input string from the user. */
+    raw: string;
+    /** The primary name of the command that was matched. */
+    name: string;
+    /** The arguments string that follows the command name. */
+    args: string;
+  };
   // Core services and configuration
   services: {
     // TODO(abhipatel12): Ensure that config is never null.
@@ -132,7 +141,7 @@ export interface SlashCommand {
   // The action to run. Optional for parent commands that only group sub-commands.
   action?: (
     context: CommandContext,
-    args: string,
+    args: string, // TODO: Remove args. CommandContext now contains the complete invocation.
   ) =>
     | void
     | SlashCommandActionReturn