chore(nix): remove deprecated packages

- Remove opencode flake input (old v1.4.3 URL, superseded)
- Remove code2prompt package
- Remove opencode-desktop package

pkgs/default.nix

@@ -18,7 +18,6 @@ in {
 
   sidecar = pkgs.callPackage ./sidecar {};
   td = pkgs.callPackage ./td {};
-  code2prompt = pkgs.callPackage ./code2prompt {};
   eigent = pkgs.callPackage ./eigent {};
   hyprpaper-random = pkgs.callPackage ./hyprpaper-random {};
   launch-webapp = pkgs.callPackage ./launch-webapp {};
@@ -39,13 +38,4 @@ in {
 
   basecamp = inputs.basecamp.packages.${system}.default;
   openspec = inputs.openspec.packages.${system}.default;
-
-  # ── Modified packages ────────────────────────────────────────────
-  # Imported from flake inputs but built with local overrides.
-
-  # inputs.opencode is used for:
-  #   - opencode binary (copied into the Tauri sidecars directory)
-  #   - node_modules (with FOD hash fix for upstream issue #11755)
-  #   - src + patches (via inputs.opencode)
-  opencode-desktop = pkgs.callPackage ./opencode-desktop {inherit inputs;};
 }