feat(claude): respawn panes on account set/unset + safe --purge (T-480 part 2)

The extension consumer for the per-repo account verbs, making set/unset
fully functional. The Claude extension subscribes to accountActionChannel:

- set / unset → ClaudeSessionOrchestrator.respawnForWorkspace(cwd): closes the
  workspace's solo sessions (awaiting real process death, T-437) and re-spawns
  each on the same id with --resume, so the conversation continues under the
  newly-bound CLAUDE_CONFIG_DIR (resolved at spawn by agentBootstrap). Team and
  forked sessions are skipped — re-joining the broker / re-forking on an account
  swap is out of scope; they adopt the account on their next natural spawn.
- remove --purge → deletes the config dir behind isPurgeableAccountDir, a strict
  guard that only ever removes a ~/.claude-* directory that is a direct child of
  $HOME. The purge payload now carries the dir (the account is gone from the
  registry by publish time).

login still only publishes its action — spawning the `claude login` terminal
pane needs argv+env terminal-pane support and is split to T-485.

Covered: respawnForWorkspace (respawn solo, skip fork/other-repo) and the purge
guard's accept/reject matrix.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/builtin/claude/src/account_registry.dart

@@ -153,6 +153,18 @@ class AccountRegistry {
   }
 }
 
+/// Whether [dir] is safe to `rm -rf` as a purged account config dir
+/// (`remove --purge`, T-480): it must be a `~/.claude-*` directory that is a
+/// DIRECT child of [home]. Anything else — an absolute path elsewhere, a nested
+/// path, the real `~/.claude` — is rejected even though the path came from our
+/// own registry. A wrong recursive delete is unrecoverable, so the predicate
+/// is deliberately strict.
+bool isPurgeableAccountDir(String dir, String home) {
+  if (home.isEmpty) return false;
+  final base = dir.split('/').last;
+  return dir == '$home/$base' && base.startsWith('.claude-');
+}
+
 /// Bootstrap probe (T-483): existing `~/.claude-*` directories that look like a
 /// Claude config dir (have a `.claude.json` file or a `sessions/` dir), as
 /// adoption candidates. Pure read — mutates nothing; the welcome view (T-481)

lib/builtin/claude/src/extension.dart

@@ -17,6 +17,7 @@ import 'package:clide/builtin/claude/src/stream_json_session.dart' show kEffortL
 import 'package:clide/builtin/claude/src/session_storage.dart';
 import 'package:clide/builtin/claude/src/ticket_pick_up.dart';
 import 'package:clide/builtin/claude/src/transcript_reader.dart' show ImageMessage;
+import 'package:clide/src/daemon/claude_account_commands.dart' show accountActionChannel;
 import 'package:clide/src/daemon/image_commands.dart' show imageShowChannel;
 import 'package:clide/builtin/claude/src/team_chat_sidebar.dart' show TeamChatPane;
 import 'package:clide/builtin/claude/src/team_panel_host.dart';
@@ -487,6 +488,42 @@ class ClaudeExtension extends ClideExtension {
     // A sidebar "pick up" click (T-327) publishes the full ticket; inject it
     // into the active conversation as a user turn so Claude starts working it.
     _subs.add(ctx.messages.subscribe(publisher: 'builtin.tickets', channel: 'pick-up').listen(_onTicketPickUp));
+
+    // `clide claude account set/unset/remove --purge` (T-480): the dispatcher
+    // writes the registry then publishes here; only the UI layer can respawn
+    // the workspace's panes onto the newly-bound account or delete a config dir.
+    _subs.add(ctx.messages.subscribe(channel: accountActionChannel).listen(_onAccountAction));
+  }
+
+  /// Side-effects for the `claude account` verbs (T-480). The dispatcher does
+  /// the registry write and publishes the action here; respawning panes,
+  /// deleting a config dir, and (future) the login terminal pane are UI-layer
+  /// concerns the Flutter-free handler can't do itself.
+  void _onAccountAction(Message m) {
+    switch (m.data['action'] as String?) {
+      case 'set':
+      case 'unset':
+        final cwd = m.data['cwd'] as String?;
+        final orch = _orchestrator;
+        if (cwd != null && orch != null) unawaited(orch.respawnForWorkspace(cwd));
+      case 'purge':
+        final dir = m.data['dir'] as String?;
+        if (dir != null) unawaited(_purgeAccountDir(dir));
+      // 'login' would spawn a `CLAUDE_CONFIG_DIR=<dir> claude login` terminal
+      // pane; that needs argv+env pane support in the terminal builtin and is
+      // wired separately. The action is published for that consumer.
+    }
+  }
+
+  /// Delete a purged account's config dir (`remove --purge`). Guarded: only a
+  /// `~/.claude-*` directory that is a direct child of the user's home is ever
+  /// removed — never an arbitrary path, even though the dir came from our own
+  /// registry. A `rm -rf` of the wrong dir is unrecoverable.
+  Future<void> _purgeAccountDir(String dir) async {
+    final home = Platform.environment['HOME'];
+    if (home == null || !isPurgeableAccountDir(dir, home)) return;
+    final d = Directory(dir);
+    if (await d.exists()) await d.delete(recursive: true);
   }
 
   /// Hand a picked-up ticket to the active Claude session (T-327/T-339). The

lib/builtin/claude/src/session_orchestrator.dart

@@ -318,6 +318,31 @@ class ClaudeSessionOrchestrator extends ChangeNotifier {
     notifyListeners();
   }
 
+  /// Respawn the workspace's solo sessions in place so they pick up a changed
+  /// per-repo Claude account (T-480). Each is closed (awaits real process
+  /// death, T-437) then re-spawned on the SAME id with `--resume` of its real
+  /// session id, so the conversation continues under the newly-bound
+  /// `CLAUDE_CONFIG_DIR` (resolved at spawn time by [agentBootstrap] from the
+  /// [accountRegistry]). Team / forked sessions are skipped — re-joining the
+  /// broker or re-forking on an account swap is out of scope; they adopt the
+  /// new account on their next natural spawn.
+  Future<void> respawnForWorkspace(String cwd) async {
+    final targets = _sessions.values.where((s) => s.cwd == cwd && s.memberName == null && s.forkSourceSessionId == null).toList();
+    for (final s in targets) {
+      final spec = SpawnSpec(
+        id: s.id,
+        role: s.role,
+        sessionId: s.sessionId,
+        cwd: s.cwd,
+        resume: true,
+        transcriptPath: claudeTranscriptPath(s.cwd, s.sessionId),
+        visible: s.visible,
+      );
+      await close(s.id);
+      await spawn(spec);
+    }
+  }
+
   /// Kill and forget a session (the real teardown). The conversation's
   /// onDispose kills the process + closes its streams; we then AWAIT the
   /// session's teardown so the `claude` process is genuinely dead before we

lib/src/daemon/claude_account_commands.dart

@@ -114,13 +114,15 @@ Future<IpcResponse> _dispatch(IpcRequest req, AccountStore? store, MessagePublis
 
     case 'remove':
       if (name == null || name.isEmpty) return _err(req.id, 'account remove requires a <name>');
-      if (_byName(store, name) == null) return _err(req.id, 'no such account: "$name"');
+      final removing = _byName(store, name);
+      if (removing == null) return _err(req.id, 'no such account: "$name"');
       if (store.boundAccountNames().contains(name)) {
         return _err(req.id, 'account "$name" is bound to a workspace', hint: 'clide claude account unset (in that workspace) first');
       }
       await store.remove(name);
       // The dir delete is IO the extension owns (this handler is Flutter-free).
-      if (purge) publish?.call('cli', accountActionChannel, {'action': 'purge', 'name': name});
+      // Carry the dir in the payload — the account is gone from the registry now.
+      if (purge) publish?.call('cli', accountActionChannel, {'action': 'purge', 'name': name, 'dir': removing.dir});
       return _ok(req.id, {'removed': name, 'purge': purge});
 
     case 'set':