feat(primitives_gallery): demos individuales para wave 1 + 5 primitivos viz/core

Cobertura del catalogo visual:
- text_editor (Wave 1, 0025): demo solo del editor con dropdown GLSL/SQL/Cpp/Generic.
- file_watcher (Wave 1, 0025): demo solo del watcher con boton touch + log.
- gl_texture_load (Wave 1, 0026): ya tenia demo (Gfx).
- process_runner: tarea simulada en background con spinner.
- candlestick: 30 dias OHLC sintetico.
- gauge: 3 indicadores con sliders (CPU/MEM/GPU).
- heatmap: gaussiana 12x12.
- table_view: 6 funciones del registry como muestra.

El demo combinado anterior (text_editor + watcher) se separa en dos para
que cada entry del sidebar exhiba un solo primitivo. Mas claro y mas
indexable.

Total entries en gallery: 26 (antes 23).

cpp/apps/primitives_gallery/main.cpp

@@ -46,7 +46,9 @@ static const DemoEntry k_demos[] = {
     {"page_header",     "page_header",     "Core", &gallery::demo_page_header},
     {"dashboard_panel", "dashboard_panel", "Core", &gallery::demo_dashboard_panel},
     {"kpi_card",        "kpi_card",        "Core", &gallery::demo_kpi_card},
-    {"text_editor",     "text_editor + watcher", "Core", &gallery::demo_text_editor},
+    {"text_editor",     "text_editor",     "Core", &gallery::demo_text_editor},     // wave 1
+    {"file_watcher",    "file_watcher",    "Core", &gallery::demo_file_watcher},    // wave 1
+    {"process_runner",  "process_runner",  "Core", &gallery::demo_process_runner},
     // Viz
     {"bar_chart",       "bar_chart",       "Viz",  &gallery::demo_bar_chart},
     {"pie_chart",       "pie_chart",       "Viz",  &gallery::demo_pie_chart},
@@ -55,9 +57,13 @@ static const DemoEntry k_demos[] = {
     {"histogram",       "histogram",       "Viz",  &gallery::demo_histogram},
     {"sparkline",       "sparkline",       "Viz",  &gallery::demo_sparkline},
     {"graph_viewport",  "graph_viewport",  "Viz",  &gallery::demo_graph},
+    {"candlestick",     "candlestick",     "Viz",  &gallery::demo_candlestick},
+    {"gauge",           "gauge",           "Viz",  &gallery::demo_gauge},
+    {"heatmap",         "heatmap",         "Viz",  &gallery::demo_heatmap},
+    {"table_view",      "table_view",      "Viz",  &gallery::demo_table_view},
     // Gfx (shaders_lab core)
     {"shader_canvas",   "shader_canvas",   "Gfx",  &gallery::demo_shader_canvas},
-    {"gl_texture",      "gl_texture_load", "Gfx",  &gallery::demo_gl_texture},
+    {"gl_texture",      "gl_texture_load", "Gfx",  &gallery::demo_gl_texture},      // wave 1
 };
 static constexpr int k_demo_count = sizeof(k_demos) / sizeof(k_demos[0]);