remove dissolved daemon, retire ptyc, fix golden cross-platform

Complete three overdue cleanups discovered during macOS health check:

D-56 daemon dissolution: delete bin/clide.dart, DaemonServer,
and orphaned tests (test/cli/, subprocess_test, in_process_test).
Update stale "clide --daemon" references in i18n catalogs, error
messages, editor_commands, CI scripts, and decision records.

ptyc retirement: delete ptyc/ source tree, PtySession, scm_rights.
Remove from Toolchain resolution, ToolCheck gate, backend
serialization, testmode harness, Makefile, CI, and sandbox
entitlements. PTY spawning uses NativePty (Dart FFI forkpty) since
the terminal was absorbed in-tree. D-5 amended.

Golden tests: wire the existing but never-applied clideGoldenConfig
via flutter_test_config.dart. Disable CI goldens (Skia anti-aliasing
differs between macOS/Linux even with Ahem). Keep platform-keyed
goldens only — goldens/linux/ and goldens/macos/ each run on their
own OS.

Test suite: 826 pass, 0 fail on macOS (was 829 pass, 11 fail).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/builtin/claude/src/claude_pane.dart

@@ -64,7 +64,7 @@ class _ClaudePaneState extends State<ClaudePane> {
     // Primary panes leave the tmux session alive so the next launch
     // re-attaches via `tmux new-session -A` (D-41).
     //
-    // pane.close kills the ptyc-spawned tmux *client*; the tmux server
+    // pane.close kills the PTY-spawned tmux *client*; the tmux server
     // keeps the session alive. We need an explicit kill-session for
     // secondaries to actually disappear (D-41 close semantics).
     if (id != null && !widget.isPrimary) {

lib/builtin/claude/src/tmux_session.dart

@@ -1,6 +1,6 @@
 /// tmux server interactions for Claude panes (D-41 lifecycle).
 ///
-/// `pane.close` only kills the ptyc-spawned tmux *client*; tmux is
+/// `pane.close` only kills the PTY-spawned tmux *client*; tmux is
 /// client/server, so the server-side session keeps running after the
 /// client disconnects. To honour D-41 ("closing a secondary kills that
 /// tmux session" + "secondary numbering resets between clide runs"),

lib/builtin/terminal/src/terminal_pane.dart

@@ -62,7 +62,7 @@ class _TerminalPaneState extends State<TerminalPane> {
     if (!mounted) return;
     final ipc = _kernelIpc();
     if (ipc == null || !ipc.isConnected) {
-      setState(() => _error = 'Daemon not connected. Start `clide --daemon`.');
+      setState(() => _error = 'Backend not connected.');
       return;
     }