refactor: encapsulate RunState internal threading fields

Mark _stop_requested, _pause_event, and _reload_requested with
init=False, repr=False, compare=False to properly encapsulate
internal control state. These fields are only accessed through
properties and methods — they should not appear in the constructor,
repr output, or equality comparisons.

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

Author: 2 people

src/ralphify/_run_types.py

@@ -87,9 +87,9 @@ class RunState:
     timed_out: int = 0  # subset of ``failed``; see class docstring
     started_at: datetime | None = None
 
-    _stop_requested: bool = False
-    _pause_event: threading.Event = field(default_factory=threading.Event)
-    _reload_requested: bool = False
+    _stop_requested: bool = field(default=False, init=False, repr=False, compare=False)
+    _pause_event: threading.Event = field(default_factory=threading.Event, init=False, repr=False, compare=False)
+    _reload_requested: bool = field(default=False, init=False, repr=False, compare=False)
 
     @property
     def total(self) -> int: