Binding preload plan

Goals

• Move all engine bindings to package.preload and require them explicitly from Lua/Fennel.
• Keep module names direct (no root namespace), and use wrapper suffixes only when needed.
• Use module factory functions instead of .new constructors while keeping usertypes for methods.

Plan

1. Convert C++ bindings to package.preload modules.

   • Status: done for appdirs, audio, callbacks, colors, fs, gl, glm, http, json, jobs, keyring, notify, ray-box, shaders, textures, terminal, input-state, tray, tree-sitter, vector-buffer, webbrowser, bt, and force-layout.

2. Update Fennel/Lua to require bindings explicitly.

   • Status: done; keep new modules aligned by adding (local x (require :x)) at the top.
   • Coverage:
     • appdirs: done
     • audio: done
     • bt: done
     • colors: done
     • fs: done
     • gl: done
     • glm: done
     • http: done
     • input-state: done
     • json: done
     • keyring: done
     • notify: done
     • ray-box: done
     • shaders: done
     • terminal: done
     • textures: done
     • tray: done
     • tree-sitter: done
     • vector-buffer: done
     • webbrowser: done
     • jobs: done
     • callbacks: done
     • force-layout: done

3. Keep wrapper naming consistent with roles.

   • Status: done (terminal-widget, input-state-router, tray-manager, notify-manager).

4. Replace .new constructors with factories.

   • Status: done for terminal.Terminal(...), VectorBuffer(...), ForceLayout(...), bt.*(...).

5. Update docs/tests to match module names and factory usage.

   • Status: done; update docs when new bindings or factories change.