Show app version in the GUI sidebar (0.0.3)

Display v<version> (from __version__) beneath the Live indicator in the sidebar.
Bump version to 0.0.3 and update CHANGELOG.

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

src/rigdoctor/__init__.py

@@ -1,3 +1,3 @@
 """RigDoctor — modular hardware monitoring & crash diagnostics for Linux gamers."""
 
-__version__ = "0.0.2"
+__version__ = "0.0.3"

src/rigdoctor/gui/main_window.py

@@ -15,6 +15,7 @@ from PySide6.QtWidgets import (
     QWidget,
 )
 
+from .. import __version__
 from .dashboard import Dashboard
 from .recorder_page import RecorderPage
 from .theme import ACCENT, MUTED
@@ -91,6 +92,9 @@ class MainWindow(QMainWindow):
         v.addStretch(1)
         live = QLabel(f'<span style="color:{ACCENT};">●</span> <span style="color:{MUTED};">Live</span>')
         v.addWidget(live)
+        version = QLabel(f"v{__version__}")
+        version.setObjectName("Muted")
+        v.addWidget(version)
         return bar
 
     def _placeholder_page(self, title: str, description: str) -> QWidget: