feat(interface): show resume hint on user-initiated exit

When the user shuts down a run (Ctrl+C in CLI, Ctrl+Q / quit dialog
in TUI, or an uncaught exception during the scan), print a Rich
panel telling them the exact command to pick up where they left off:

    strix --run-name <run_name>

The panel only appears when ``strix_runs/<run_name>/bus.json``
exists — i.e. the scan registered at least the root agent and has
snapshot state worth resuming from. Suppressed when:

  * No run-name was assigned (Ctrl+C before sandbox bring-up).
  * The run dir doesn't exist or has no bus.json yet.

Implementation:

  * ``strix/interface/utils.py`` gains ``format_resume_hint(run_name)
    -> Panel | None``.
  * ``cli.py`` calls it in the SIGINT/SIGTERM/SIGHUP handler before
    ``sys.exit(1)``, and in the ``except Exception`` arm before the
    re-raise.
  * ``tui.py:run_tui`` calls it in a ``finally`` after
    ``app.run_async()`` so the hint lands on the real terminal once
    Textual has restored it (whether the user pressed Ctrl+Q,
    confirmed the quit dialog, or the run completed naturally).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

strix/interface/cli.py

@@ -21,6 +21,7 @@ from strix.telemetry.tracer import Tracer, set_global_tracer
 
 from .utils import (
     build_live_stats_text,
+    format_resume_hint,
     format_vulnerability_report,
 )
 
@@ -139,6 +140,10 @@ async def run_cli(args: Any) -> None:  # noqa: PLR0915
 
     def signal_handler(_signum: int, _frame: Any) -> None:
         tracer.cleanup()
+        hint = format_resume_hint(args.run_name)
+        if hint is not None:
+            console.print()
+            console.print(hint)
         sys.exit(1)
 
     atexit.register(cleanup_on_exit)
@@ -212,6 +217,10 @@ async def run_cli(args: Any) -> None:  # noqa: PLR0915
 
     except Exception as e:
         console.print(f"[bold red]Error during penetration test:[/] {e}")
+        hint = format_resume_hint(args.run_name)
+        if hint is not None:
+            console.print()
+            console.print(hint)
         raise
 
     if tracer.final_scan_result:

strix/interface/tui.py

@@ -35,7 +35,7 @@ from strix.config import load_settings
 from strix.interface.tool_components.agent_message_renderer import AgentMessageRenderer
 from strix.interface.tool_components.registry import get_tool_renderer
 from strix.interface.tool_components.user_message_renderer import UserMessageRenderer
-from strix.interface.utils import build_tui_stats_text
+from strix.interface.utils import build_tui_stats_text, format_resume_hint
 from strix.orchestration.scan import run_strix_scan
 from strix.runtime import session_manager
 from strix.telemetry.tracer import Tracer, set_global_tracer
@@ -1991,4 +1991,16 @@ class StrixTUIApp(App):  # type: ignore[misc]
 async def run_tui(args: argparse.Namespace) -> None:
     """Run strix in interactive TUI mode with textual."""
     app = StrixTUIApp(args)
-    await app.run_async()
+    try:
+        await app.run_async()
+    finally:
+        # After Textual restores the real terminal, print the resume
+        # hint so the user knows the exact ``strix --run-name X``
+        # invocation that picks up where they left off.
+        from rich.console import Console
+
+        hint = format_resume_hint(getattr(args, "run_name", None))
+        if hint is not None:
+            console = Console()
+            console.print()
+            console.print(hint)

strix/interface/utils.py

@@ -1449,3 +1449,37 @@ def validate_config_file(config_path: str) -> Path:
         sys.exit(1)
 
     return path
+
+
+def format_resume_hint(run_name: str | None) -> Panel | None:
+    """Tell the user how to resume the current run, if it persisted state.
+
+    Returns a Rich :class:`Panel` ready to ``console.print`` when
+    ``strix_runs/<run_name>/bus.json`` exists (i.e. the scan registered
+    at least the root agent and has snapshot state to resume from).
+    Returns ``None`` when there's nothing to resume — e.g. the user hit
+    Ctrl+C before sandbox bring-up, or no run-name was assigned yet.
+
+    Mirrors the auto-resume contract in ``orchestration/scan.py``:
+    re-running with the same ``--run-name`` picks up where this scan
+    left off; deleting ``strix_runs/<run_name>/`` forces a fresh start.
+    """
+    if not run_name:
+        return None
+    run_dir = Path("strix_runs") / run_name
+    if not (run_dir / "bus.json").exists():
+        return None
+
+    text = Text()
+    text.append("Run paused. Resume any time with:\n\n", style="white")
+    text.append(f"  strix --run-name {run_name}\n", style="bold #60a5fa")
+    text.append("\nOr delete ", style="dim")
+    text.append(f"strix_runs/{run_name}/", style="bold dim")
+    text.append(" to start fresh.", style="dim")
+    return Panel(
+        text,
+        title="[bold white]STRIX",
+        title_align="left",
+        border_style="#60a5fa",
+        padding=(1, 2),
+    )