replace watchdog with active polling thread

watchdog does not work on windows. For some
reason file modification events are not
emitted.
Fixed by replacing watchdog with a thread
that polls the modification date ever 0.5s.

Also fixed a bug that the hit view was not
properly destructed.

.idea/misc.xml

@@ -3,5 +3,5 @@
   <component name="Black">
     <option name="sdkName" value="Python 3.12 (krowlog)" />
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.12 (krowlog)" project-jdk-type="Python SDK" />
+  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.12 (krowlog) (2)" project-jdk-type="Python SDK" />
 </project>

.idea/ravenlog.iml

@@ -10,7 +10,7 @@
       <excludeFolder url="file://$MODULE_DIR$/icons-not-used" />
       <excludeFolder url="file://$MODULE_DIR$/venv312" />
     </content>
-    <orderEntry type="jdk" jdkName="Python 3.12 (krowlog)" jdkType="Python SDK" />
+    <orderEntry type="jdk" jdkName="Python 3.12 (krowlog) (2)" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>