Major changes: logic add to panel, local variables, panel histor, users management...

internal/datasource/synthetic/definition.go

@@ -10,6 +10,16 @@ type SignalDef struct {
 	Inputs   []InputRef    `json:"inputs"`  // alternative multi-input format
 	Pipeline []NodeDef     `json:"pipeline"` // ordered list of DSP nodes
 	Meta     MetaOverride  `json:"meta"`    // optional metadata overrides
+
+	// Visibility controls who sees this signal in the signal tree:
+	//   "global"      — listed in every panel's edit mode
+	//   "user"        — listed in every panel owned by Owner
+	//   "panel"       — listed only when editing the bound Panel
+	// An empty value is treated as "global" for backward compatibility with
+	// definitions created before this field existed.
+	Visibility string `json:"visibility,omitempty"`
+	Owner      string `json:"owner,omitempty"` // creator identity (stamped server-side)
+	Panel      string `json:"panel,omitempty"` // bound interface id for "panel" visibility
 }
 
 // InputRef names one upstream signal used as input to the pipeline.