Add missing icon and improve plugin verification

- Add picocode.png icon file to resources/icons/
- Restore icon reference in plugin.xml
- Add verifyPlugin task to CI to validate plugin structure
- Build logs already uploaded with if: always() condition

Co-authored-by: Mte90 <403283+Mte90@users.noreply.github.com>

Author: Copilot

.github/workflows/kotlin-ci.yml

@@ -63,7 +63,7 @@ jobs:
           GRADLE_OPTS: "-Dorg.gradle.jvmargs=-Xmx3g"
         run: |
           set -o pipefail
-          ./gradlew buildPlugin --no-daemon --stacktrace 2>&1 | tee ../gradle-build.log
+          ./gradlew buildPlugin verifyPlugin --no-daemon --stacktrace 2>&1 | tee ../gradle-build.log
         working-directory: ide-plugins
 
       - name: Upload build log

ide-plugins/src/main/resources/META-INF/plugin.xml

@@ -13,6 +13,7 @@
     <extensions defaultExtensionNs="com.intellij">
         <toolWindow id="PicoCode RAG"
                     secondary="true"
+                    icon="/icons/picocode.png"
                     anchor="right"
                     factoryClass="com.picocode.PicoCodeToolWindowFactory"/>
         <statusBarWidgetFactory implementation="com.picocode.PicoCodeStatusBarWidgetFactory"