fix(bild): per-module builds + exit code propagation

- Fix nixBuild to propagate exit code from realise step
  - Previously used >> which discarded exit code - Now checks realise
  result before running symlink - Fixes false success checkmarks on
  build failures

- Fix per-module Nix derivations
  - Use cp -rL instead of tar (src is directory not tarball) - Add
  coreutils and findutils to pkgs - Copy deps to . and use -i. for
  GHC - Use find with --parents to preserve module hierarchy - Set
  dontStrip=true to avoid fixup script errors

- Tested: Example.hs, Task.hs, Dragons.hs, Bild.hs all build - Known
issue: makeWrapper fixup scripts have unbound vars (Nix bug)

1 files changed, 3 insertions, 0 deletions

diff --git a/Omni/Bild.nix b/Omni/Bild.nix
index adacb97..6a7b87f 100644
--- a/Omni/Bild.nix
+++ b/Omni/Bild.nix
@@ -113,17 +113,20 @@
         bat
         bc
         cmark
+        coreutils
         universal-ctags
         datasette
         deadnix
         fd
         figlet
+        findutils
         ffmpeg
         fzf
         git
         git-branchless
         gitlint
         gitstats
+        gnutar
         groff
         guile
         hlint