Simplify CI/CD pipeline with CronJob-based build trigger

- Add CronJob that polls git repository every 2 minutes for changes
- Automatically triggers Kaniko build jobs when new commits detected
- Images tagged with both 'latest' and 'v1.0.<commit-sha>' for versioning
- Remove complex Tekton/Flux image automation dependencies
- Add comprehensive simple CI/CD setup documentation

This provides a reliable, simple CI/CD pipeline:
1. Push code to Gitea
2. CronJob detects changes within 2 minutes
3. Kaniko builds and pushes to Harbor
4. Flux deploys latest image automatically

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

flux-imagepolicy.yaml

@@ -10,5 +10,5 @@ spec:
     semver:
       range: '>=1.0.0'
   filterTags:
-    pattern: '^v?(?P<version>[0-9]+\.[0-9]+\.[0-9]+)$'
+    pattern: '^v(?P<version>[0-9]+\.[0-9]+\.[a-f0-9]+)$'
     extract: '$version'