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-kustomization-build.yaml

@@ -0,0 +1,36 @@
+---
+apiVersion: kustomize.toolkit.fluxcd.io/v1
+kind: Kustomization
+metadata:
+  name: neon-vortex-build
+  namespace: flux-system
+spec:
+  interval: 5m
+  path: ./
+  prune: false
+  sourceRef:
+    kind: GitRepository
+    name: neon-vortex
+  targetNamespace: default
+  patches:
+    - patch: |
+        apiVersion: batch/v1
+        kind: Job
+        metadata:
+          name: neon-vortex-build
+          namespace: default
+        spec:
+          template:
+            metadata:
+              name: neon-vortex-build
+      target:
+        kind: Job
+        name: neon-vortex-build
+  postBuild:
+    substitute:
+      GIT_COMMIT: "unknown"
+  healthChecks:
+    - apiVersion: batch/v1
+      kind: Job
+      name: neon-vortex-build
+      namespace: default