Proposal: Reorganize Nix packages (lem as full-featured, lem-ncurses as minimal)

[cxxxr]

Background

In PR #2024, @tani suggested merging lem-webview into lem-cli:

do you have any plan to contain merge lem-webview nix package into lem-cli? I prefer do that.

#2024 (review)

Current Structure

Package	Contents
lem (lem-cli)	ncurses + SDL2
lem-webview	WebKit GUI

Proposed Structure

Package	Contents	Use Case
lem	ncurses + SDL2 + webview	Desktop users (full-featured)
lem-ncurses	ncurses only	Server / minimal environments

Benefits

1. Intuitive naming: lem provides all features out of the box
2. Addresses @tani's feedback: Integration of frontends
3. Lightweight option available: lem-ncurses for minimal environments
4. Simple: 2 packages cover all use cases

Concerns

1. Heavier default: nix run github:lem-project/lem would download WebKitGTK (~hundreds of MB)
2. macOS compatibility: WebKitGTK is Linux-focused. May need conditional logic:

   lem = if pkgs.stdenv.isLinux 
         then lem-full      # Linux: all frontends
         else lem-cli;      # macOS: SDL2 + ncurses only

3. SDL2-only option: Users who want SDL2 without ncurses or webview would need a separate package

Alternative: 3-package structure

Package	Contents	Notes
lem	ncurses + SDL2	Current default, most portable
lem-ncurses	ncurses only	Minimal
lem-full	All frontends	Linux only

Questions for Discussion

1. Should lem be the full-featured package or stay as ncurses + SDL2?
2. Do we need a SDL2-only package?
3. How should we handle macOS where webview may not work?

/cc @tani

[cxxxr]

Note: This issue was created based on a conversation with Claude Code.

[tani]

Note that lem-sdl2 is broken on macOS due to the issue that sdl2 misses cl-gult.