feat(cli): show YOLO mode warning in banner and status bar

When running with --yolo, all dangerous command approvals are bypassed.
Make this state visible so users don't forget:

- Banner: '⚠ YOLO mode — all approval prompts bypassed' line in red, only
  shown when YOLO is active. Default case is silent (no extra line, no
  always-on 'restricted' label).
- Status bar: '⚠ YOLO' fragment appended in red (#FF4444 bold) across all
  three width tiers (<52, <76, ≥76) in both the plain-text fallback and
  the fragments builder.

Closes #2663

Co-authored-by: Mibayy <Mibayy@users.noreply.github.com>

hermes_cli/banner.py

@@ -470,6 +470,9 @@ def build_welcome_banner(console: Console, model: str, cwd: str,
         model_short = model_short[:25] + "..."
     ctx_str = f" [dim {dim}]·[/] [dim {dim}]{_format_context_length(context_length)} context[/]" if context_length else ""
     left_lines.append(f"[{accent}]{model_short}[/]{ctx_str} [dim {dim}]·[/] [dim {dim}]Nous Research[/]")
+
+    if os.getenv("HERMES_YOLO_MODE"):
+        left_lines.append(f"[bold red]⚠ YOLO mode[/] [dim {dim}]— all approval prompts bypassed[/]")
     left_lines.append(f"[dim {dim}]{cwd}[/]")
     if session_id:
         left_lines.append(f"[dim {session_color}]Session: {session_id}[/]")