Add JSON schema generation for kubeconform CRD validation (#212)

## Summary
- New `ci/generate-schemas.sh` script that generates JSON schemas from three sources:
  1. Live cluster CRDs via `kubectl get crds`
  2. Offline CRD manifests (ArgoCD v3.3.2, Gateway API v1.5.1)
  3. Kubernetes v1.33.7 swagger spec for native types
- Schemas follow Datree catalog convention (`<group>/<Kind>_<version>.json`)
- `validate-apps.sh` and `validate-clusters.sh` check local schemas first, falling back to remote
- Fixes TLSRoute (and other CRD) schema validation failures in kubeconform

## Sources
- ArgoCD: `artifactapi.../argoproj/argo-cd/refs/tags/v3.3.2/manifests/ha/install.yaml`
- Gateway API: `artifactapi.../kubernetes-sigs/gateway-api/releases/download/v1.5.1/standard-install.yaml`
- Kubernetes: `artifactapi.../kubernetes/kubernetes/refs/tags/v1.33.7/api/openapi-spec/swagger.json`

Reviewed-on: #212
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

.pre-commit-config.yaml

@@ -7,6 +7,7 @@ repos:
       - id: check-json
       - id: check-added-large-files
         args: ['--maxkb=500']
+        exclude: '^schemas/'
       - id: check-merge-conflict
       - id: check-shebang-scripts-are-executable
       - id: check-symlinks
@@ -19,6 +20,7 @@ repos:
       - id: end-of-file-fixer
       - id: forbid-new-submodules
       - id: pretty-format-json
+        args: ['--autofix']
       - id: trailing-whitespace
 
   # YAML linting