fix: address review feedback on PR #106

- Remove unused envOrDefaultBool function and its test (Sonnet #3266 NIT)
- Replace Unicode em dashes with ASCII in slog messages (GPT #3267 NIT)
- Add scheme validation for vcsURL before embedding in Markdown link
  (Security #3269 MINOR — defense-in-depth against unsafe schemes)
- Extract ReviewerSelfRequester interface to remove concrete gitea.Adapter
  dependency from main's self-reviewer path (Sonnet #3266 NIT)
- Add compile-time conformance assertion and test for Adapter.RequestReviewerSelf

gitea/adapter.go

@@ -16,6 +16,7 @@ type Adapter struct {
 
 // Compile-time interface conformance assertion.
 var _ vcs.Client = (*Adapter)(nil)
+var _ vcs.ReviewerSelfRequester = (*Adapter)(nil)
 
 // NewAdapter creates a new Adapter wrapping the given gitea Client.
 func NewAdapter(client *Client) *Adapter {
@@ -230,3 +231,9 @@ func (a *Adapter) DismissReview(ctx context.Context, owner, repo string, number
 func (a *Adapter) GetAuthenticatedUser(ctx context.Context) (string, error) {
 	return a.client.GetAuthenticatedUser(ctx)
 }
+
+// RequestReviewerSelf adds the given user as a requested reviewer on a pull request.
+// This implements vcs.ReviewerSelfRequester for the Gitea adapter.
+func (a *Adapter) RequestReviewerSelf(ctx context.Context, owner, repo string, number int, user string) error {
+	return a.client.RequestReviewer(ctx, owner, repo, number, user)
+}