Restructure as monorepo and add flake packages/apps

- Move Elixir code to server/ subdirectory for monorepo structure
- Update flake.nix to provide packages and apps outputs for nix run support
- Update nix/package.nix to accept src parameter instead of fetchgit
- Add NixOS module export for easy consumption

Now supports: nix run, nix build, and nix develop from git repo

🤖 Generated with [Claude Code](https://claude.ai/code)

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

server/_build/dev/lib/jason/ebin/jason.app

@@ -0,0 +1,26 @@
+{application,jason,
+             [{modules,['Elixir.Enumerable.Jason.OrderedObject',
+                        'Elixir.Jason','Elixir.Jason.Codegen',
+                        'Elixir.Jason.DecodeError','Elixir.Jason.Decoder',
+                        'Elixir.Jason.Decoder.Unescape','Elixir.Jason.Encode',
+                        'Elixir.Jason.EncodeError','Elixir.Jason.Encoder',
+                        'Elixir.Jason.Encoder.Any',
+                        'Elixir.Jason.Encoder.Atom',
+                        'Elixir.Jason.Encoder.BitString',
+                        'Elixir.Jason.Encoder.Date',
+                        'Elixir.Jason.Encoder.DateTime',
+                        'Elixir.Jason.Encoder.Float',
+                        'Elixir.Jason.Encoder.Integer',
+                        'Elixir.Jason.Encoder.Jason.Fragment',
+                        'Elixir.Jason.Encoder.Jason.OrderedObject',
+                        'Elixir.Jason.Encoder.List',
+                        'Elixir.Jason.Encoder.Map',
+                        'Elixir.Jason.Encoder.NaiveDateTime',
+                        'Elixir.Jason.Encoder.Time','Elixir.Jason.Formatter',
+                        'Elixir.Jason.Fragment','Elixir.Jason.Helpers',
+                        'Elixir.Jason.OrderedObject','Elixir.Jason.Sigil']},
+              {optional_applications,[decimal]},
+              {applications,[kernel,stdlib,elixir,decimal]},
+              {description,"A blazing fast JSON parser and generator in pure Elixir.\n"},
+              {registered,[]},
+              {vsn,"1.4.4"}]}.