Implement new middleware interfaces for all middleware (#1422)

This provides implementations of the new interfaces for all the middleware in our codebase.

This does change over the code yet, that will happen in the next PR. Some unused code is commented out to allow the larger PR to be split up.

Author: dmjb

CLAUDE.md

@@ -199,3 +199,4 @@ Follow conventional commit format:
   - Refer to the `CONTRIBUTING.md` file for guidelines on commit message format
     conventions.
   - Do not use "Conventional Commits", e.g. starting with `feat`, `fix`, `chore`, etc.
+  - Use mockgen for creating mocks instead of generating mocks by hand.

pkg/audit/middleware.go

@@ -0,0 +1,76 @@
+package audit
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/stacklok/toolhive/pkg/transport/types"
+)
+
+// Middleware type constant
+const (
+	MiddlewareType = "audit"
+)
+
+// MiddlewareParams represents the parameters for audit middleware
+type MiddlewareParams struct {
+	ConfigPath string  `json:"config_path,omitempty"` // Kept for backwards compatibility
+	ConfigData *Config `json:"config_data,omitempty"` // New field for config contents
+	Component  string  `json:"component,omitempty"`
+}
+
+// Middleware wraps audit middleware functionality
+type Middleware struct {
+	middleware types.MiddlewareFunction
+}
+
+// Handler returns the middleware function used by the proxy.
+func (m *Middleware) Handler() types.MiddlewareFunction {
+	return m.middleware
+}
+
+// Close cleans up any resources used by the middleware.
+func (*Middleware) Close() error {
+	// Audit middleware doesn't need cleanup
+	return nil
+}
+
+// CreateMiddleware factory function for audit middleware
+func CreateMiddleware(config *types.MiddlewareConfig, runner types.MiddlewareRunner) error {
+
+	var params MiddlewareParams
+	if err := json.Unmarshal(config.Parameters, &params); err != nil {
+		return fmt.Errorf("failed to unmarshal audit middleware parameters: %w", err)
+	}
+
+	var auditConfig *Config
+	var err error
+
+	if params.ConfigData != nil {
+		// Use provided config data (preferred method)
+		auditConfig = params.ConfigData
+	} else if params.ConfigPath != "" {
+		// Load config from file (backwards compatibility)
+		auditConfig, err = LoadFromFile(params.ConfigPath)
+		if err != nil {
+			return fmt.Errorf("failed to load audit configuration: %w", err)
+		}
+	} else {
+		// Use default config
+		auditConfig = DefaultConfig()
+	}
+
+	// Set component name if provided
+	if params.Component != "" {
+		auditConfig.Component = params.Component
+	}
+
+	middleware, err := auditConfig.CreateMiddleware()
+	if err != nil {
+		return fmt.Errorf("failed to create audit middleware: %w", err)
+	}
+
+	auditMw := &Middleware{middleware: middleware}
+	runner.AddMiddleware(auditMw)
+	return nil
+}