feat: graph_explorer app — agnostic operations.db viewer (issue 0049k)

App C++ ImGui que abre cualquier operations.db del registry y lo visualiza
como grafo con shapes/iconos/layouts/filtros/labels.

Composicion del registry:
- viz/graph_renderer + graph_force_layout(_gpu) + graph_layouts +
  graph_viewport + graph_labels + graph_icons + graph_sources
- core: toolbar, modal_dialog, select, text_input, tree_view, page_header,
  fullscreen_window, button, badge, empty_state

Capas:
- data.{h,cpp}    — dispatcher GraphLoadFn (operations hoy; json/graphml manana).
- types_registry.{h,cpp} — parser YAML minimal + tabler_codepoint_by_name +
  apply_types_yaml + IconAtlas builder.
- views.{h,cpp}   — Toolbar, Legend, Inspector, Stats, modal Filters/Open.
- layout_store.{h,cpp} — graph_explorer.db SQLite con tabla layouts(graph_hash,
  node_id, x, y, pinned, updated_at). UPSERT por nodo.
- main.cpp        — CLI (--input/--types/--layout) + fn::run_app + bucle
  force layout (CPU/GPU toggle) + render con 3 columnas (Legend / Viewport /
  Inspector+Stats).

examples/types.yaml: 10 entidades OSINT (Person/Email/Domain/Phone/Org/IBAN/
Account/Document/Address/Url) + 5 relaciones (owns/knows/located_in/
transfers_to/member_of) con shapes Tabler reales.

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

data.cpp

@@ -0,0 +1,35 @@
+#include "data.h"
+
+#include <cstdio>
+#include <cstring>
+
+namespace ge {
+
+bool load_graph(const InputArgs& args, GraphData* out, graph::GraphLoadStats* stats) {
+    if (!out || !stats) return false;
+    *stats = graph::GraphLoadStats{};
+    if (!args.uri || !*args.uri) {
+        stats->errors = 1;
+        std::snprintf(stats->error_msg, sizeof(stats->error_msg),
+                      "no input uri");
+        return false;
+    }
+
+    switch (args.kind) {
+        case INPUT_OPERATIONS:
+            return graph::graph_load_from_operations(args.uri, out, stats);
+        case INPUT_NONE:
+        default:
+            stats->errors = 1;
+            std::snprintf(stats->error_msg, sizeof(stats->error_msg),
+                          "unsupported input kind");
+            return false;
+    }
+}
+
+bool reload_graph(const InputArgs& args, GraphData* out, graph::GraphLoadStats* stats) {
+    if (out) graph::graph_free(out);
+    return load_graph(args, out, stats);
+}
+
+} // namespace ge