feat: add multi-server support via GITEA_SERVERS env var

Allows connecting to multiple Gitea instances from a single MCP server.
Set GITEA_SERVERS as a JSON object mapping names to {host, token, insecure}
configs. Every tool gets an optional "server" parameter, and a new
"list_servers" tool is added to discover available connections.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pkg/gitea/gitea.go

@@ -12,16 +12,16 @@ import (
 	"gitea.com/gitea/gitea-mcp/pkg/flag"
 )
 
-func NewClient(token string) (*gitea.Client, error) {
+func newClientForHost(host, token string, insecure bool) (*gitea.Client, error) {
 	httpClient := &http.Client{
-		Transport:     http.DefaultTransport,
+		Transport:     http.DefaultTransport.(*http.Transport).Clone(),
 		CheckRedirect: checkRedirect,
 	}
 
 	opts := []gitea.ClientOption{
 		gitea.SetToken(token),
 	}
-	if flag.Insecure {
+	if insecure {
 		httpClient.Transport.(*http.Transport).TLSClientConfig = &tls.Config{
 			InsecureSkipVerify: true,
 		}
@@ -30,16 +30,20 @@ func NewClient(token string) (*gitea.Client, error) {
 	if flag.Debug {
 		opts = append(opts, gitea.SetDebugMode())
 	}
-	client, err := gitea.NewClient(flag.Host, opts...)
+	client, err := gitea.NewClient(host, opts...)
 	if err != nil {
 		return nil, fmt.Errorf("create gitea client err: %w", err)
 	}
 
-	// Set user agent for the client
 	client.SetUserAgent("gitea-mcp-server/" + flag.Version)
 	return client, nil
 }
 
+// NewClient creates a Gitea client using the default host and the given token.
+func NewClient(token string) (*gitea.Client, error) {
+	return newClientForHost(flag.Host, token, flag.Insecure)
+}
+
 // checkRedirect prevents Go from silently changing mutating requests (POST, PATCH, etc.)
 // to GET when following 301/302/303 redirects, which would drop the request body and
 // make writes appear to succeed when they didn't.
@@ -53,10 +57,21 @@ func checkRedirect(_ *http.Request, via []*http.Request) error {
 	return nil
 }
 
+// ClientFromContext creates a Gitea client using connection details from the
+// context (set by the multi-server wrapper) or falling back to global defaults.
 func ClientFromContext(ctx context.Context) (*gitea.Client, error) {
-	token, ok := ctx.Value(mcpContext.TokenContextKey).(string)
-	if !ok {
-		token = flag.Token
+	host := flag.Host
+	token := flag.Token
+	insecure := flag.Insecure
+
+	if h, ok := ctx.Value(mcpContext.HostContextKey).(string); ok && h != "" {
+		host = h
 	}
-	return NewClient(token)
+	if t, ok := ctx.Value(mcpContext.TokenContextKey).(string); ok && t != "" {
+		token = t
+	}
+	if i, ok := ctx.Value(mcpContext.InsecureContextKey).(bool); ok {
+		insecure = i
+	}
+	return newClientForHost(host, token, insecure)
 }