feat(viz): graph_types modelo extendido + EntityType/RelationType + flags (issue 0049e)

Extiende el modelo agnostico de graph_types.h para soportar shapes/iconos/
filtros/labels/streaming sin acoplar a backend. Migra el unico consumer
(demos_graph) en el mismo cambio.

- GraphNode v2: type_id + shape_override/color_override/size_override +
  flags (NF_PINNED/VISIBLE/SELECTED/HOVERED) + label_idx + user_data.
- GraphEdge v2: type_id + style_override + flags (EF_DIRECTED/VISIBLE).
- EntityType / RelationType: tablas en GraphData (types, rel_types).
- Helpers de resolucion (resolve_node_color/shape/size, resolve_edge_*)
  y constructores ergonomicos (graph_node, graph_edge, entity_type,
  relation_type) — sentinel-based para herencia automatica del tipo.
- graph_renderer v1.4: lee NF_VISIBLE / EF_VISIBLE, resuelve apariencia
  via override → EntityType → fallback indexado por type_id. Skipea
  aristas con endpoints invisibles. Shapes siguen pintandose como
  circulo (0049f cableara el dispatch real).
- graph_force_layout v1.2: pinned ahora vive en flags & NF_PINNED.
- graph_viewport v1.1: hover/seleccion publican NF_HOVERED/SELECTED en
  el grafo (clear-then-set). Drag usa NF_PINNED. Tooltip muestra Type/
  user_data en lugar de community/value/label.
- demos_graph: 8 EntityType (paleta antigua) + 1 RelationType. type_id
  por cluster. user_data = indice numerico del nodo. Apariencia visual
  identica al pre-cambio.
- test_graph_types.cpp: 12 casos cubriendo helpers, defaults, bitmask
  manipulation y resoluciones override-vs-EntityType. test_graph_edge_
  static actualizado al nuevo modelo (ya no tiene .color directo).
- 4 .md de tipos nuevos (graph_node, graph_edge, entity_type,
  relation_type) + GraphData v2.0 actualizado.

Tests: 31/31 ctest verdes (incluye test_visual golden).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

cpp/functions/viz/graph_viewport.cpp

@@ -139,7 +139,8 @@ bool graph_viewport(const char* id, GraphData& graph, GraphViewportState& state,
         for (int i = 0; i < graph.node_count; ++i) {
             xs_buf[i] = graph.nodes[i].x;
             ys_buf[i] = graph.nodes[i].y;
-            sz_buf[i] = graph.nodes[i].size;
+            sz_buf[i] = resolve_node_size(graph.nodes[i],
+                                           graph.types, graph.type_count);
         }
         state.spatial->build(xs_buf.data(), ys_buf.data(), sz_buf.data(), graph.node_count);
     }
@@ -216,12 +217,20 @@ bool graph_viewport(const char* id, GraphData& graph, GraphViewportState& state,
     // -------------------------------------------------------------------
     // 5c. Hover — query nearest node
     // -------------------------------------------------------------------
+    // Clear-then-set: limpiamos NF_HOVERED del nodo previo aunque el cursor
+    // ya no este sobre el viewport (cambio de target). Esto evita que el
+    // flag persista cuando el usuario sale del widget.
+    int prev_hovered = state.hovered_node;
+    if (prev_hovered >= 0 && prev_hovered < graph.node_count) {
+        graph.nodes[prev_hovered].flags &= ~NF_HOVERED;
+    }
     state.hovered_node = -1;
     if (hovered && graph.node_count > 0) {
         float hit_radius = 10.0f / state.zoom;
         int nearest = state.spatial->query_nearest(gx_mouse, gy_mouse, hit_radius);
         if (nearest >= 0) {
             state.hovered_node = nearest;
+            graph.nodes[nearest].flags |= NF_HOVERED;
             interacted = true;
         }
     }
@@ -237,7 +246,7 @@ bool graph_viewport(const char* id, GraphData& graph, GraphViewportState& state,
     } else {
         // Release drag
         if (state.drag_node >= 0 && state.drag_node < graph.node_count) {
-            graph.nodes[state.drag_node].pinned = false;
+            graph.nodes[state.drag_node].flags &= ~NF_PINNED;
         }
         state.drag_node   = -1;
         state.is_dragging = false;
@@ -249,15 +258,21 @@ bool graph_viewport(const char* id, GraphData& graph, GraphViewportState& state,
         n.y      = gy_mouse;
         n.vx     = 0.0f;
         n.vy     = 0.0f;
-        n.pinned = true;
+        n.flags |= NF_PINNED;
         interacted = true;
     }
 
     // -------------------------------------------------------------------
-    // 5e. Click — select node
+    // 5e. Click — select node (clear-then-set NF_SELECTED)
     // -------------------------------------------------------------------
     if (hovered && lm_click && state.drag_node == -1) {
+        if (state.selected_node >= 0 && state.selected_node < graph.node_count) {
+            graph.nodes[state.selected_node].flags &= ~NF_SELECTED;
+        }
         state.selected_node = state.hovered_node;
+        if (state.selected_node >= 0 && state.selected_node < graph.node_count) {
+            graph.nodes[state.selected_node].flags |= NF_SELECTED;
+        }
         interacted = true;
     }
 
@@ -309,11 +324,15 @@ bool graph_viewport(const char* id, GraphData& graph, GraphViewportState& state,
         }
 
         ImGui::BeginTooltip();
-        if (n.label) ImGui::TextUnformatted(n.label);
-        ImGui::Text("ID: %u", n.id);
-        ImGui::Text("Community: %u", n.community);
+        if (graph.types && n.type_id < (uint16_t)graph.type_count
+                       && graph.types[n.type_id].name) {
+            ImGui::Text("Type: %s", graph.types[n.type_id].name);
+        } else {
+            ImGui::Text("Type: %u", (unsigned)n.type_id);
+        }
+        ImGui::Text("Index: %d", state.hovered_node);
+        if (n.user_data) ImGui::Text("user_data: %llu", (unsigned long long)n.user_data);
         ImGui::Text("Degree: %d", degree);
-        ImGui::Text("Value: %.3f", n.value);
         ImGui::EndTooltip();
     }