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

Infra ADR-0004 renamed the Gitea host. Bulk replace across go.mod and
all .go import paths. Build and tests pass unchanged.

Closes #20

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dt6aHEDWRjkK14Voi6HnGh

internal/web/account.go

@@ -3,7 +3,7 @@ package web
 import (
 	"net/http"
 
-	"gitea.d-ma.be/mathias/tapir/internal/adapters/store"
+	"git.d-ma.be/mathias/tapir/internal/adapters/store"
 )
 
 // handleAccount renders the account page: the user's display name, the