Split laptop/work into independent stow packages with shared/ base

- Remove work/laptop detection logic from nvim and emacs configs; each
  package now has a self-contained init that requires no runtime checks
- Create shared/ stow package containing nvim/init.lua, emacs/init.el,
  common-dev-settings.el, org-bindings.el, tmux, ghostty, and ranger
- Rename laptop-languages.lua / work-languages.lua → languages.lua in
  each package; shared/init.lua uses require('languages') generically
- Rename work-dev-settings.el → dev-settings.el to match laptop naming
- Expand work/ to include the full set of dev tools (tmux, ghostty,
  ranger, emacs, neovim) without email/calendar tooling
- Add Makefile with `make laptop` and `make work` targets (each runs
  a single `stow shared <profile>` invocation)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

laptop/.config/nvim/lua/languages.lua

@@ -0,0 +1,19 @@
+-- Laptop language pack: C/C++, Go, Rust, LaTeX, DAP.
+-- Loaded by shared/init.lua via require('languages').
+
+
+return {
+  servers = {
+    clangd        = {},
+    gopls         = {},
+    rust_analyzer = {},
+  },
+  parsers   = { 'c', 'cpp', 'go', 'latex', 'rust' },
+  formatters = {
+    go   = { 'goimports', 'gofmt' },
+    rust = { 'rustfmt' },
+    c    = { 'clang_format' },
+    cpp  = { 'clang_format' },
+  },
+  tools = { 'clang-format', 'codelldb' },
+}