core/cli: multi-line boxed tool confirm prompts

Echo a terminal-width box with wrapped reason (argv / -c code) before a
short Allow? y/N prompt so shell confirms are not jammed on one line.

tests/test_cli/test_limits.py

@@ -1,6 +1,11 @@
 from __future__ import annotations
 
-from plyngent.cli.limits import install_cli_limit_hooks, prompt_confirm_tool, prompt_continue_limit
+from plyngent.cli.limits import (
+    format_tool_confirm_box,
+    install_cli_limit_hooks,
+    prompt_confirm_tool,
+    prompt_continue_limit,
+)
 from plyngent.prompting import get_prompt_backend, temporary_backend
 from plyngent.tools.process.pty_session import PtyManager
 from tests.test_prompting import ScriptedBackend
@@ -24,6 +29,17 @@ def test_prompt_confirm_tool_default_deny() -> None:
         assert prompt_confirm_tool("delete_path", {"path": "x"}, "delete path 'x'") is False
 
 
+def test_format_tool_confirm_box_multiline() -> None:
+    reason = "run_command: python3 -c (review code before allow)\nargv:\n  python3 -c print(1)\n-c code:\n  print(1)"
+    box = format_tool_confirm_box("run_command", reason)
+    assert "┌" in box and "└" in box
+    assert "confirm · tool 'run_command'" in box
+    assert "python3 -c" in box
+    assert "print(1)" in box
+    # Distinct lines, not one jammed row
+    assert box.count("\n") >= 4
+
+
 def test_install_cli_limit_hooks() -> None:
     install_cli_limit_hooks()
     assert callable(getattr(PtyManager, "_limit_continue", None))