Add complete CI/CD pipeline with Tekton and Flux image automation

- Add Tekton pipeline and triggers for automated builds on git push
- Add Flux ImageRepository to track Harbor registry images
- Add Flux ImagePolicy for semantic versioning strategy
- Add Flux ImageUpdateAutomation to auto-update HelmRelease
- Update HelmRelease with image automation marker
- Add comprehensive CI/CD pipeline setup documentation

This enables automatic build and deployment when pushing to Gitea:
1. Gitea webhook triggers Tekton pipeline
2. Kaniko builds and pushes image to Harbor
3. Flux detects new image and updates deployment
4. Application automatically deploys to cluster

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

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

flux-helmrelease.yaml

@@ -17,5 +17,5 @@ spec:
     image:
       registry: images.caffeinetux.com
       repository: apps/neon-vortex
-      tag: latest
+      tag: latest # {"$imagepolicy": "flux-system:neon-vortex:tag"}
       pullPolicy: Always