feat: add unified IM access policies

src/channels/shared/command-permission.mjs

@@ -0,0 +1,32 @@
+import { isBatchInputCommand } from './batch-input.mjs';
+import { isCompactCommand } from './compact-command.mjs';
+import { isControlCommand } from './control-command.mjs';
+import { isHistoryCommand } from './history-command.mjs';
+import { isModelCommand } from './model-command.mjs';
+import { isPresetCommand } from './preset-command.mjs';
+import { isWorkspaceCommand } from './workspace-command.mjs';
+
+const SIMPLE_TEXT_COMMANDS = new Set(['/help', '/status', '/new']);
+
+/**
+ * Match only commands that the shared bridges already execute locally.
+ * Unknown slash-prefixed text remains an ordinary prompt.
+ */
+export function isSharedLocalCommand(text, {
+  hasImages = false,
+  hasFiles = false,
+} = {}) {
+  if (typeof text !== 'string') return false;
+  const command = text.trim();
+  if (!command) return false;
+  if (isBatchInputCommand(command) || isHistoryCommand(command)) return true;
+  if (!hasFiles && (
+    isControlCommand(command)
+    || isModelCommand(command)
+    || isPresetCommand(command)
+  )) return true;
+  if (hasImages || hasFiles) return false;
+  return SIMPLE_TEXT_COMMANDS.has(command.toLowerCase())
+    || isWorkspaceCommand(command)
+    || isCompactCommand(command);
+}