Nix build fixes:
- Override beamPackages.elixir to use 1.19.5 instead of default 1.18.4
- Add explicit buildPhase to compile dependencies before application
- Remove postInstall phase (Mix automatically includes priv/ in release)
- Set HEX_OFFLINE=false to allow dependency fetching in Nix sandbox
Docker image build now succeeds (~507 MB compressed).
Also remove .claude/settings.local.json from git tracking (keep local).
File remains in working directory but is now properly ignored.
Add git and cacert to nativeBuildInputs and set SSL certificate
environment variables. This fixes the SSL certificate verification
error when fetching heroicons from GitHub.
Override configurePhase to explicitly run 'mix deps.get' before
compilation. This ensures hex dependencies (like ecto) are available
when vendored path dependencies (oban_met) are compiled.
The postUnpack step was deleting deps directories which may have
been removing vendored dependencies. cleanSourceWith already handles
source filtering, so postUnpack is redundant and potentially harmful.
Remove buggy conditional that was always true. Now the filter
correctly excludes only build artifacts while including all
source files including vendor directory.
Replace sourceFilesBySuffices with cleanSourceWith to ensure
vendor directory and all dependencies are properly included.
This fixes the oban_met compilation error.
Instead of hardcoding the version in the path, find the release
directory dynamically. This fixes the 'undefined variable version'
error during Docker image build.
