feat(profiles): refactor profiles to centralize logic in core

Centralized profile loading and management in packages/core.
Updated CLI commands to use core ProfileManager.
Implemented persistent profile selection in loadCliConfig.
Standardized profile format as Markdown with YAML frontmatter.
Verified multi-extension loading with 'coder' profile.

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

@@ -0,0 +1,147 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  type CommandContext,
+  type SlashCommand,
+  type SlashCommandActionReturn,
+  CommandKind,
+} from './types.js';
+import { type HistoryItemProfilesList, MessageType } from '../types.js';
+import { getErrorMessage } from '../../utils/errors.js';
+import {
+  listProfiles,
+  switchProfile,
+  getActiveProfile,
+} from '@google/gemini-cli-core';
+
+async function listAction(
+  context: CommandContext,
+  args: string,
+): Promise<void | SlashCommandActionReturn> {
+  const subArgs = args.trim().split(/\s+/);
+  let useShowDescriptions = true;
+
+  for (const arg of subArgs) {
+    if (arg === 'nodesc' || arg === '--nodesc') {
+      useShowDescriptions = false;
+    }
+  }
+
+  const config = context.services.config;
+  if (!config) {
+    context.ui.addItem({
+      type: MessageType.ERROR,
+      text: 'Could not retrieve configuration.',
+    });
+    return;
+  }
+
+  const profiles = listProfiles(config);
+  const activeProfile = getActiveProfile(config);
+
+  const profilesListItem: HistoryItemProfilesList = {
+    type: MessageType.PROFILES_LIST,
+    profiles,
+    activeProfileName: activeProfile?.name,
+    showDescriptions: useShowDescriptions,
+  };
+
+  context.ui.addItem(profilesListItem);
+}
+
+async function switchAction(
+  context: CommandContext,
+  args: string,
+): Promise<void | SlashCommandActionReturn> {
+  const profileName = args.trim();
+  if (!profileName) {
+    context.ui.addItem({
+      type: MessageType.ERROR,
+      text: 'Please provide a profile name to switch to.',
+    });
+    return;
+  }
+
+  const config = context.services.config;
+  if (!config) {
+    context.ui.addItem({
+      type: MessageType.ERROR,
+      text: 'Could not retrieve configuration.',
+    });
+    return;
+  }
+
+  try {
+    await switchProfile(config, profileName);
+    context.ui.addItem({
+      type: MessageType.INFO,
+      text: `Switched to profile: ${profileName}`,
+    });
+  } catch (error) {
+    context.ui.addItem({
+      type: MessageType.ERROR,
+      text: `Failed to switch profile: ${getErrorMessage(error)}`,
+    });
+  }
+}
+
+async function reloadAction(
+  context: CommandContext,
+): Promise<void | SlashCommandActionReturn> {
+  const config = context.services.config;
+  if (!config) {
+    context.ui.addItem({
+      type: MessageType.ERROR,
+      text: 'Could not retrieve configuration.',
+    });
+    return;
+  }
+
+  try {
+    await config.getProfileManager().load();
+    context.ui.addItem({
+      type: MessageType.INFO,
+      text: 'Profiles reloaded successfully.',
+    });
+  } catch (error) {
+    context.ui.addItem({
+      type: MessageType.ERROR,
+      text: `Failed to reload profiles: ${getErrorMessage(error)}`,
+    });
+  }
+}
+
+export const profilesCommand: SlashCommand = {
+  name: 'profiles',
+  description:
+    'List, switch, or reload Gemini CLI profiles. Usage: /profiles [list | switch <name> | reload]',
+  kind: CommandKind.BUILT_IN,
+  autoExecute: false,
+  subCommands: [
+    {
+      name: 'list',
+      description: 'List available profiles. Usage: /profiles list [nodesc]',
+      kind: CommandKind.BUILT_IN,
+      action: listAction,
+    },
+    {
+      name: 'switch',
+      description:
+        'Switch to a profile by name. Usage: /profiles switch <name>',
+      kind: CommandKind.BUILT_IN,
+      action: switchAction,
+    },
+    {
+      name: 'reload',
+      description:
+        'Reload the list of discovered profiles. Usage: /profiles reload',
+      kind: CommandKind.BUILT_IN,
+      action: reloadAction,
+    },
+  ],
+  action: listAction,
+};