fix(helm): add missing metrics configuration to values.schema.json (#1382)

PR #1313 added metrics configuration to values.yaml but did not update
values.schema.json, causing helm template validation to fail with:
'Additional property metrics is not allowed'

This commit adds the metrics property definition to the schema including:
- enabled: boolean to toggle metrics collection
- port: integer for metrics endpoint port
- serviceMonitor: object for Prometheus Operator integration
- customLabels: object for custom metric labels

Fixes schema validation error introduced in PR #1313
Related to Feature #218 (Prometheus Metrics Instrumentation)

Signed-off-by: ppippi-dev <[email protected]>

Author: ppippi-dev

charts/mcp-stack/values.schema.json

@@ -132,6 +132,45 @@
           "maximum": 65535,
           "default": 4444
         },
+        "metrics": {
+          "type": "object",
+          "description": "Metrics configuration",
+          "properties": {
+            "enabled": {
+              "type": "boolean",
+              "description": "Enable metrics collection",
+              "default": true
+            },
+            "port": {
+              "type": "integer",
+              "description": "Metrics port",
+              "minimum": 1,
+              "maximum": 65535,
+              "default": 8000
+            },
+            "serviceMonitor": {
+              "type": "object",
+              "description": "ServiceMonitor configuration for Prometheus Operator",
+              "properties": {
+                "enabled": {
+                  "type": "boolean",
+                  "description": "Enable ServiceMonitor creation",
+                  "default": true
+                }
+              },
+              "additionalProperties": false
+            },
+            "customLabels": {
+              "type": "object",
+              "description": "Custom labels for metrics",
+              "additionalProperties": {
+                "type": "string"
+              },
+              "default": {}
+            }
+          },
+          "additionalProperties": false
+        },
         "probes": {
           "type": "object",
           "description": "Health probe configuration",