feat: visualize beam spread around peaks

schemas/result.schema.json

@@ -66,10 +66,48 @@
         "sourceId": { "type": "string", "minLength": 1 },
         "position": { "$ref": "#/$defs/position" },
         "value": { "type": "number", "minimum": 0 },
+        "beamSpread": { "$ref": "#/$defs/beamSpread" },
         "localizationErrorM": { "type": "number", "minimum": 0 },
         "localizationErrorPixels": { "type": "number", "minimum": 0 }
       }
     },
+    "beamSpread": {
+      "type": "object", "additionalProperties": false,
+      "required": [
+        "calibrated", "method", "halfPowerRatio", "thresholdValue", "pixelCount",
+        "centroid", "covarianceM2", "ellipse"
+      ],
+      "properties": {
+        "calibrated": { "const": false },
+        "method": { "const": "connected-half-power-power-weighted-covariance" },
+        "halfPowerRatio": { "type": "number", "exclusiveMinimum": 0, "maximum": 1 },
+        "thresholdValue": { "type": "number", "minimum": 0 },
+        "pixelCount": { "type": "integer", "minimum": 0, "maximum": 262144 },
+        "centroid": { "$ref": "#/$defs/position" },
+        "covarianceM2": {
+          "type": "object", "additionalProperties": false,
+          "required": ["xx", "xy", "yy"],
+          "properties": {
+            "xx": { "type": "number", "minimum": 0 },
+            "xy": { "type": "number" },
+            "yy": { "type": "number", "minimum": 0 }
+          }
+        },
+        "ellipse": {
+          "type": "object", "additionalProperties": false,
+          "required": [
+            "axisScale", "angleReference", "majorRmsRadiusM", "minorRmsRadiusM", "angleDeg"
+          ],
+          "properties": {
+            "axisScale": { "const": "rms" },
+            "angleReference": { "const": "counterclockwise-from-positive-x" },
+            "majorRmsRadiusM": { "type": "number", "minimum": 0 },
+            "minorRmsRadiusM": { "type": "number", "minimum": 0 },
+            "angleDeg": { "type": "number", "minimum": -180, "maximum": 180 }
+          }
+        }
+      }
+    },
     "evaluation": {
       "type": "object", "additionalProperties": false,
       "required": [