Persist diagram routing with atomic edits and grouped movement

crates/oa-core/src/model.rs

@@ -1241,7 +1241,29 @@ pub struct Diagram {
     pub projection: ProjectionKind,
     #[serde(deserialize_with = "unique_id_map")]
     pub nodes: BTreeMap<Id, NodePlacement>,
+    #[serde(default)]
+    pub routes: Vec<EdgeRoute>,
 }
+/// Authored presentation for one existing relation or trace in one diagram.
+/// Computed endpoints and automatic routing elbows are never persisted here.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct EdgeRoute {
+    pub edge: Id,
+    #[serde(default)]
+    pub waypoints: Vec<Position>,
+    #[serde(default)]
+    pub label: Option<EdgeLabel>,
+}
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct EdgeLabel {
+    /// Fraction of the computed polyline's total arc length, from source to target.
+    pub fraction: f32,
+    /// Diagram-space displacement relative to the point at `fraction`.
+    pub offset: Position,
+}
+pub const MAX_ROUTE_POINTS: usize = 128;
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct NodePlacement {
@@ -1613,6 +1635,7 @@ impl Project {
                 layer,
                 projection: ProjectionKind::Overview,
                 nodes: BTreeMap::new(),
+                routes: vec![],
             },
         );
         id