Add production-grade Helm chart improvements

High-impact improvements based on Codex recommendations:

1. values.schema.json - JSON schema validation catches config errors at install time
2. helm-docs automation - Auto-generates documentation from values.yaml comments
3. kind smoke tests - Deploys and upgrades chart in real cluster to catch runtime issues
4. ServiceMonitor template - Built-in Prometheus integration for observability
5. Artifact Hub metadata - Changelog, links, and maintainer info for better discoverability

These improvements provide:
- Configuration validation before deployment
- Always up-to-date documentation
- Runtime validation in CI
- First-class monitoring support
- Better user experience on Artifact Hub

Related to #686

deploy/helm/pulse/values.schema.json

@@ -0,0 +1,189 @@
+{
+  "$schema": "https://json-schema.org/draft-07/schema#",
+  "type": "object",
+  "required": ["server"],
+  "properties": {
+    "replicaCount": {
+      "type": "integer",
+      "minimum": 1,
+      "description": "Number of Pulse server replicas"
+    },
+    "image": {
+      "type": "object",
+      "properties": {
+        "repository": {
+          "type": "string",
+          "description": "Container image repository"
+        },
+        "pullPolicy": {
+          "type": "string",
+          "enum": ["Always", "IfNotPresent", "Never"],
+          "description": "Image pull policy"
+        },
+        "tag": {
+          "type": "string",
+          "description": "Container image tag (overrides chart appVersion)"
+        }
+      }
+    },
+    "imagePullSecrets": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "properties": {
+          "name": {
+            "type": "string"
+          }
+        }
+      },
+      "description": "Image pull secrets for private registries"
+    },
+    "service": {
+      "type": "object",
+      "properties": {
+        "type": {
+          "type": "string",
+          "enum": ["ClusterIP", "NodePort", "LoadBalancer"],
+          "description": "Kubernetes service type"
+        },
+        "port": {
+          "type": "integer",
+          "minimum": 1,
+          "maximum": 65535,
+          "description": "Service port"
+        }
+      }
+    },
+    "ingress": {
+      "type": "object",
+      "properties": {
+        "enabled": {
+          "type": "boolean",
+          "description": "Enable ingress resource"
+        },
+        "className": {
+          "type": "string",
+          "description": "Ingress class name"
+        },
+        "hosts": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "host": {
+                "type": "string",
+                "format": "hostname"
+              },
+              "paths": {
+                "type": "array",
+                "items": {
+                  "type": "object",
+                  "properties": {
+                    "path": {
+                      "type": "string"
+                    },
+                    "pathType": {
+                      "type": "string",
+                      "enum": ["Prefix", "Exact", "ImplementationSpecific"]
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "persistence": {
+      "type": "object",
+      "properties": {
+        "enabled": {
+          "type": "boolean",
+          "description": "Enable persistent storage"
+        },
+        "existingClaim": {
+          "type": "string",
+          "description": "Use existing PVC"
+        },
+        "storageClass": {
+          "type": "string",
+          "description": "Storage class name"
+        },
+        "accessMode": {
+          "type": "string",
+          "enum": ["ReadWriteOnce", "ReadOnlyMany", "ReadWriteMany", "ReadWriteOncePod"],
+          "description": "PVC access mode"
+        },
+        "size": {
+          "type": "string",
+          "pattern": "^[0-9]+[EPTGMK]i?$",
+          "description": "Storage size (e.g., 8Gi)"
+        }
+      }
+    },
+    "server": {
+      "type": "object",
+      "properties": {
+        "resources": {
+          "type": "object",
+          "description": "Resource requests and limits"
+        },
+        "env": {
+          "type": "array",
+          "description": "Environment variables"
+        },
+        "secretEnv": {
+          "type": "object",
+          "properties": {
+            "create": {
+              "type": "boolean"
+            },
+            "name": {
+              "type": "string"
+            },
+            "data": {
+              "type": "object"
+            }
+          }
+        }
+      }
+    },
+    "agent": {
+      "type": "object",
+      "properties": {
+        "enabled": {
+          "type": "boolean",
+          "description": "Enable Docker monitoring agent"
+        },
+        "kind": {
+          "type": "string",
+          "enum": ["DaemonSet", "Deployment"],
+          "description": "Agent deployment type"
+        }
+      }
+    },
+    "monitoring": {
+      "type": "object",
+      "properties": {
+        "serviceMonitor": {
+          "type": "object",
+          "properties": {
+            "enabled": {
+              "type": "boolean",
+              "description": "Create ServiceMonitor for Prometheus"
+            },
+            "interval": {
+              "type": "string",
+              "pattern": "^[0-9]+[smh]$",
+              "description": "Scrape interval (e.g., 30s)"
+            },
+            "path": {
+              "type": "string",
+              "description": "Metrics endpoint path"
+            }
+          }
+        }
+      }
+    }
+  }
+}