chore(module): rename gitea.d-ma.be → git.d-ma.be module path

The host rename broke `go mod download` for consumers: the server serves a
go-import meta tag of git.d-ma.be/... which no longer matches the old
gitea.d-ma.be/... import path (hyperguild #74). Rename the module path to
match. Single leaf package (auth/), no internal self-imports — go.mod +
README example only. Tagged v0.2.0; v0.1.0 (old path) left intact for
unmigrated consumers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -48,7 +48,7 @@ import (
 	"net/http"
 	"os"
 
-	"gitea.d-ma.be/mathias/mcp-chassis/auth"
+	"git.d-ma.be/mathias/mcp-chassis/auth"
 )
 
 func main() {
@@ -82,7 +82,7 @@ func mcpHandler() http.Handler { /* per-domain */ return nil }
 ## Versioning
 
 Trunk-based development on `main`. Tagged with semver. Consumers pin
-specific tags (`go.mod` `require gitea.d-ma.be/mathias/mcp-chassis v0.x.y`)
+specific tags (`go.mod` `require git.d-ma.be/mathias/mcp-chassis v0.x.y`)
 and bump deliberately.
 
 Migrations are documented per-consumer in the consumer's CHANGELOG / commits.

go.mod

@@ -1,4 +1,4 @@
-module gitea.d-ma.be/mathias/mcp-chassis
+module git.d-ma.be/mathias/mcp-chassis
 
 go 1.26.1