feat(mcp): add SSE transport support and related configuration options

internal/config/config.go

@@ -32,6 +32,7 @@ type ServerConfig struct {
 
 type MCPConfig struct {
 	Path           string        `yaml:"path"`
+	SSEPath        string        `yaml:"sse_path"`
 	ServerName     string        `yaml:"server_name"`
 	Version        string        `yaml:"version"`
 	Transport      string        `yaml:"transport"`

internal/config/loader.go

@@ -58,6 +58,7 @@ func defaultConfig() Config {
 		},
 		MCP: MCPConfig{
 			Path:           "/mcp",
+			SSEPath:        "/sse",
 			ServerName:     "amcs",
 			Version:        info.Version,
 			Transport:      "streamable_http",

internal/config/validate.go

@@ -33,6 +33,14 @@ func (c Config) Validate() error {
 	if strings.TrimSpace(c.MCP.Path) == "" {
 		return fmt.Errorf("invalid config: mcp.path is required")
 	}
+	if c.MCP.SSEPath != "" {
+		if strings.TrimSpace(c.MCP.SSEPath) == "" {
+			return fmt.Errorf("invalid config: mcp.sse_path must not be blank whitespace")
+		}
+		if c.MCP.SSEPath == c.MCP.Path {
+			return fmt.Errorf("invalid config: mcp.sse_path %q must differ from mcp.path", c.MCP.SSEPath)
+		}
+	}
 	if c.MCP.SessionTimeout <= 0 {
 		return fmt.Errorf("invalid config: mcp.session_timeout must be greater than zero")
 	}