docs: Gitea is the home (D-65 amended)

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

Cargo.toml

@@ -6,7 +6,7 @@ members = ["checker", "runner", "gnucash"]
 [workspace.package]
 edition = "2024"
 license = "MIT OR Apache-2.0"
-repository = "https://github.com/swaits/bookspec"
+repository = "https://git.swaits.com/swaits/bookspec"
 
 [workspace.lints.rust]
 missing_docs = "warn"