feat(framework): assets/ subfolder para distribuibles read-only

Refina la convencion de layout: el top de cada app distribuible
solo lleva el .exe + DLLs nativas; todo lo demas (TTFs, enrichers,
runtime Python, MCP servers) vive en <exe_dir>/assets/.

Cambios:
- cpp/CMakeLists.txt::add_imgui_app — copia las 5 TTFs (Karla,
  Roboto, DroidSans, Cousine, tabler-icons) a
  $<TARGET_FILE_DIR>/assets/ en lugar de junto al exe.
- framework/app_base: nuevas funciones fn::asset_dir() y
  fn::asset_path(name) que resuelven a <exe_dir>/assets/<name>.
- functions/core/icon_font.cpp::find_asset — anade
  fn::asset_path(filename) como PRIMERA ruta de busqueda, antes
  de las legacy ./<file> y ./assets/<file>. Mantiene los
  fallbacks para dev (FN_ASSETS_DIR, FN_CPP_ROOT).
- .claude/commands/compile.md — el deploy a Desktop pone TTFs +
  enrichers/ + runtime/ + gx-cli en <DEST>/assets/. Solo .exe y
  DLLs nativas (duckdb.dll) quedan en el top. local_files/ se
  preserva si existe.

Layout final:
  Desktop/apps/<APP>/
  ├── <APP>.exe + *.dll          (binario + DLLs Windows)
  ├── assets/                    (read-only distribuible)
  │   ├── *.ttf, enrichers/, runtime/, gx-cli, ...
  └── local_files/               (per-PC, creado al primer arranque)

Esto cierra la separacion conceptual de la convencion: la carpeta
es trivial de zippear (solo .exe + assets/), el reset/sync es
trivial (local_files/), y todas las apps del registry adoptan el
mismo layout via fn_framework.

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

cpp/CMakeLists.txt

@@ -154,8 +154,11 @@ add_library(fn_framework STATIC
     functions/core/panel_menu.cpp
     functions/core/layouts_menu.cpp
     functions/core/app_menubar.cpp
+    functions/core/logger.cpp
+    functions/core/log_window.cpp
     functions/gfx/gl_loader.cpp
     functions/core/layout_storage.cpp
+    functions/core/selectable_text.cpp
 )
 target_include_directories(fn_framework PUBLIC
     ${CMAKE_CURRENT_SOURCE_DIR}/framework
@@ -194,25 +197,31 @@ function(add_imgui_app target)
     target_include_directories(${target} PRIVATE
         ${FN_CPP_ROOT_DIR}/functions
     )
-    # Copia las fuentes junto al ejecutable para deploys autonomos (sin
-    # FN_CPP_ROOT en runtime). 4 TTFs vectoriales para el menu Settings + Tabler
-    # para los iconos TI_*.
+    # Convencion de layout (cpp_apps.md §7):
+    #   <exe_dir>/<app>.exe + <app>.dll     (binario + DLLs Windows convention)
+    #   <exe_dir>/assets/                   (read-only: ttfs, enrichers, runtime, etc.)
+    #   <exe_dir>/local_files/              (creado en runtime: ini, db, projects)
+    #
+    # add_imgui_app copia las TTFs a <exe_dir>/assets/. La app las
+    # encuentra en runtime via fn::asset_path() (icon_font.cpp).
+    set(_ASSETS_DIR $<TARGET_FILE_DIR:${target}>/assets)
     add_custom_command(TARGET ${target} POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E make_directory ${_ASSETS_DIR}
         COMMAND ${CMAKE_COMMAND} -E copy_if_different
                 ${FN_CPP_ROOT_DIR}/vendor/imgui/misc/fonts/Karla-Regular.ttf
-                $<TARGET_FILE_DIR:${target}>/Karla-Regular.ttf
+                ${_ASSETS_DIR}/Karla-Regular.ttf
         COMMAND ${CMAKE_COMMAND} -E copy_if_different
                 ${FN_CPP_ROOT_DIR}/vendor/imgui/misc/fonts/Roboto-Medium.ttf
-                $<TARGET_FILE_DIR:${target}>/Roboto-Medium.ttf
+                ${_ASSETS_DIR}/Roboto-Medium.ttf
         COMMAND ${CMAKE_COMMAND} -E copy_if_different
                 ${FN_CPP_ROOT_DIR}/vendor/imgui/misc/fonts/DroidSans.ttf
-                $<TARGET_FILE_DIR:${target}>/DroidSans.ttf
+                ${_ASSETS_DIR}/DroidSans.ttf
         COMMAND ${CMAKE_COMMAND} -E copy_if_different
                 ${FN_CPP_ROOT_DIR}/vendor/imgui/misc/fonts/Cousine-Regular.ttf
-                $<TARGET_FILE_DIR:${target}>/Cousine-Regular.ttf
+                ${_ASSETS_DIR}/Cousine-Regular.ttf
         COMMAND ${CMAKE_COMMAND} -E copy_if_different
                 ${FN_CPP_ROOT_DIR}/vendor/tabler-icons/tabler-icons.ttf
-                $<TARGET_FILE_DIR:${target}>/tabler-icons.ttf
+                ${_ASSETS_DIR}/tabler-icons.ttf
         VERBATIM
     )
 endfunction()