feat: implement Gitea API client

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/gitea/types.go

@@ -0,0 +1,25 @@
+package gitea
+
+type GiteaUser struct {
+	ID       int64  `json:"id"`
+	Login    string `json:"login"`
+	FullName string `json:"full_name"`
+	Email    string `json:"email"`
+}
+
+type GiteaRepo struct {
+	ID       int64      `json:"id"`
+	Name     string     `json:"name"`
+	FullName string     `json:"full_name"`
+	CloneURL string     `json:"clone_url"`
+	SSHURL   string     `json:"ssh_url"`
+	Private  bool       `json:"private"`
+	Size     int64      `json:"size"`
+	Updated  string     `json:"updated_at"`
+	Owner    *GiteaUser `json:"owner"`
+}
+
+type GiteaSearchResponse struct {
+	OK   bool        `json:"ok"`
+	Data []GiteaRepo `json:"data"`
+}