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>

schemas/crd.projectcalico.org/ippool_v1.json

@@ -0,0 +1,74 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "properties": {
+    "apiVersion": {
+      "type": "string"
+    },
+    "kind": {
+      "type": "string"
+    },
+    "metadata": {
+      "type": "object"
+    },
+    "spec": {
+      "properties": {
+        "allowedUses": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "assignmentMode": {
+          "enum": [
+            "Automatic",
+            "Manual"
+          ],
+          "type": "string"
+        },
+        "blockSize": {
+          "type": "integer"
+        },
+        "cidr": {
+          "type": "string"
+        },
+        "disableBGPExport": {
+          "type": "boolean"
+        },
+        "disabled": {
+          "type": "boolean"
+        },
+        "ipip": {
+          "properties": {
+            "enabled": {
+              "type": "boolean"
+            },
+            "mode": {
+              "type": "string"
+            }
+          },
+          "type": "object"
+        },
+        "ipipMode": {
+          "type": "string"
+        },
+        "nat-outgoing": {
+          "type": "boolean"
+        },
+        "natOutgoing": {
+          "type": "boolean"
+        },
+        "nodeSelector": {
+          "type": "string"
+        },
+        "vxlanMode": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "cidr"
+      ],
+      "type": "object"
+    }
+  },
+  "type": "object"
+}