Integrate Darwin branch features into integration branch

- Add AeroSpace window manager configuration and file setup
- Add LazyVim setup with gh-addressed plugin
- Add Darwin-specific secrets (work key + work-wg.age)
- Reorganize kitty config into separate profile
- Make Linux-only packages conditional (iputils, strace, vim-tidal)
- Fix nix-darwin compatibility (remove deprecated options, add primaryUser)
- Update font packages to new nerd-fonts structure
- Add platform-aware nrb alias (detects Darwin vs Linux)
- Use shared tmux config instead of Darwin-specific duplicate
- Update Darwin host config (disable yabai, enable AeroSpace)
- Fix sketchybar permissions and gitignore .direnv tracking

Integration branch now works on both Darwin and Linux with all Darwin improvements.

Amp-Thread-ID: https://ampcode.com/threads/T-9427454f-2ecb-40ef-998b-0f33f0950105
Co-authored-by: Amp <amp@ampcode.com>

home/darwin/default.nix

@@ -7,6 +7,7 @@
     ../profiles/git
     ../profiles/task
     ../profiles/kitty
+    ../profiles/tmux
     # ../profiles/firefox
   ];
 
@@ -14,7 +15,7 @@
   home.homeDirectory = "/Users/anishlakhwara";
   home.stateVersion = "22.05";
 
-  programs.zsh.initExtra = ''
+  programs.zsh.initContent = ''
     PATH=/Users/anishlakhwara/.sourcegraph/bin:/Users/anishlakhwara/.sourcegraph/sg.zsh_autocomplete:/Users/anishlakhwara/google-cloud-sdk/bin:/Users/anishlakhwara/google-cloud-sdk/completion.zsh.inc:/Users/anishlakhwara/google-cloud-sdk/path.zsh.inc:/Users/anishlakhwara/.sg:/opt/homebrew/bin:$PATH
     '';
 
@@ -24,5 +25,8 @@
         source = ./sketchybar;
         recursive = true;
     };
+    ".config/aerospace" = {
+      source = ./aerospace;
+    };
   };
 }