Use b for building and r for recruitment

- Replace Ctrl+Space with `b` and Alt+Space with `r` in README and
  documentation.
- Remove the old Alt+Space recruitment keybinding and adjust key
  handling code.
- Revamp skirmish view to display colored lines and updated status
  messages.
- Increase test suite to 83 tests and update test expectations for new
  shortcuts.
- Update flake.lock with the latest revision and hash.

flake.lock

@@ -8,11 +8,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1792320163,
-        "narHash": "sha256-3YqCuAdykExGnEFw44w+8qsjdOEZMBCViDpvue5ENoc=",
+        "lastModified": 1792494797,
+        "narHash": "sha256-W0hLL8YLjWT/QlHcnNbON3EeDostg+GD9fw6rv4jbyY=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "53d7844fe302be84e5e63b2ca92a2f84c6490b4e",
+        "rev": "e77f56ee0521b21e5a987dd3e88b6bb367d777a7",
         "type": "github"
       },
       "original": {
@@ -46,11 +46,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1792094642,
-        "narHash": "sha256-zp8ToDMnqZcu4o4IH9pdwXFXGp7yLm/M0dEnNWnyd7I=",
+        "lastModified": 1792502884,
+        "narHash": "sha256-IoNisKcGbUjdd45qCqywGMCYmZ5EnkxezvLII0FWwNA=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "fe13242281a67641c0102cdb1087f0ebe586c7df",
+        "rev": "02c087f3fe673c9e317f206a627cb6b910336dbe",
         "type": "github"
       },
       "original": {
@@ -70,11 +70,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1792141191,
-        "narHash": "sha256-H161gJK9JlpkP3bGnsbTdzzRcP51oiFYrHbCdsQH4kc=",
+        "lastModified": 1792431056,
+        "narHash": "sha256-FiKlJK+NoB9J9+xIQPfJaRfK42msh55Pt6FsJ++NcxY=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "70e0c46be740a471bcc95f2be290f4bbfdcffd87",
+        "rev": "7afa765037d97a62b53c59907e9f503409f2a673",
         "type": "github"
       },
       "original": {