Add complete webhook-based CI/CD with automatic builds and notifications

This commit implements a full webhook-triggered CI/CD pipeline:

**Flux Components:**
- Flux Receiver for Gitea webhooks (generic type, NodePort 30090)
- Notification Provider for notify.caffeinetux.com
- Alerts for git updates, builds, and deployments

**Build Automation:**
- Webhook listener deployment that triggers on git push
- Automatic Kaniko build jobs with git metadata
- Images tagged with both 'latest' and commit SHA
- Build notifications sent at start and completion

**Workflow:**
1. Push to Gitea → Webhooks trigger Flux receiver & build listener
2. Build listener creates Kaniko job with commit info
3. Kaniko builds and pushes to Harbor (latest + SHA tags)
4. Flux auto-deploys latest image to cluster
5. Notifications sent to notify.caffeinetux.com at each stage

**Configuration:**
- Token: APMvTuncQJmm6vd
- Webhook path: /hook/548969c2b24c717fe9e5af8c78ddfeec40d3024c270c7e85ac8f986259aeec9a
- Build trigger: http://<node-ip>:30091/webhook
- Comprehensive setup documentation in WEBHOOK_SETUP_GUIDE.md

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

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

flux-build-kustomization.yaml

@@ -0,0 +1,55 @@
+---
+apiVersion: kustomize.toolkit.fluxcd.io/v1
+kind: Kustomization
+metadata:
+  name: neon-vortex-build
+  namespace: flux-system
+spec:
+  interval: 1m
+  path: ./
+  prune: false
+  sourceRef:
+    kind: GitRepository
+    name: neon-vortex
+    namespace: flux-system
+  targetNamespace: default
+  patches:
+    - patch: |
+        apiVersion: batch/v1
+        kind: Job
+        metadata:
+          name: neon-vortex-build
+          namespace: default
+        spec:
+          template:
+            metadata:
+              annotations:
+                git-commit: "${GIT_COMMIT:-unknown}"
+            spec:
+              initContainers:
+              - name: git-clone
+                env:
+                - name: GIT_COMMIT
+                  value: "${GIT_COMMIT:-main}"
+              containers:
+              - name: kaniko
+                args:
+                - "--dockerfile=/workspace/htlm/Dockerfile"
+                - "--context=/workspace/htlm"
+                - "--destination=images.caffeinetux.com/apps/neon-vortex:latest"
+                - "--destination=images.caffeinetux.com/apps/neon-vortex:${GIT_COMMIT:-latest}"
+                - "--cache=true"
+                - "--cache-repo=images.caffeinetux.com/apps/neon-vortex/cache"
+      target:
+        kind: Job
+        name: neon-vortex-build
+  postBuild:
+    substituteFrom:
+      - kind: ConfigMap
+        name: git-commit-info
+        optional: true
+  healthChecks:
+    - apiVersion: batch/v1
+      kind: Job
+      name: neon-vortex-build
+      namespace: default