Src, move out of ./rust, add missing wip files

Moves file contents out of ./rust since I'm planning to go with rust for
the backend and the lexicons will be used for codegen soon anyways.

I also added extra files that have been in the works that I have been
accidentally sprinkling into main.rs already. God forbid I need to
cherry-pick anything from so far back in the history.

It will make git blame ugly though.

flake.lock

@@ -0,0 +1,60 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1735563628,
+        "narHash": "sha256-OnSAY7XDSx7CtDoqNh8jwVwh4xNL/2HaJxGjryLWzX8=",
+        "rev": "b134951a4c9f3c995fd7be05f3243f8ecd65d798",
+        "revCount": 637546,
+        "type": "tarball",
+        "url": "https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.2405.637546%2Brev-b134951a4c9f3c995fd7be05f3243f8ecd65d798/01941dc2-2ab2-7453-8ebd-88712e28efae/source.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://flakehub.com/f/NixOS/nixpkgs/0.2405.%2A.tar.gz"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1744536153,
+        "narHash": "sha256-awS2zRgF4uTwrOKwwiJcByDzDOdo3Q1rPZbiHQg/N38=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "18dd725c29603f582cf1900e0d25f9f1063dbf11",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_2"
+      },
+      "locked": {
+        "lastModified": 1746585402,
+        "narHash": "sha256-Pf+ufu6bYNA1+KQKHnGMNEfTwpD9ZIcAeLoE2yPWIP0=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "72dd969389583664f87aa348b3458f2813693617",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}