feat(config): add multiple server instances support

- Add ServersConfig and ServerInstanceConfig structs
- Support configuring multiple named server instances
- Add global timeout defaults with per-instance overrides
- Add TLS configuration options (SSL cert/key, self-signed, AutoTLS)
- Add validation for server configurations
- Add helper methods for applying defaults and getting default server
- Add conversion helper to avoid import cycles

pkg/config/paths.go

@@ -0,0 +1,117 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// Get retrieves a path by name
+func (pc PathsConfig) Get(name string) (string, error) {
+	if pc == nil {
+		return "", fmt.Errorf("paths not initialized")
+	}
+
+	path, ok := pc[name]
+	if !ok {
+		return "", fmt.Errorf("path '%s' not found", name)
+	}
+
+	return path, nil
+}
+
+// GetOrDefault retrieves a path by name, returning defaultPath if not found
+func (pc PathsConfig) GetOrDefault(name, defaultPath string) string {
+	if pc == nil {
+		return defaultPath
+	}
+
+	path, ok := pc[name]
+	if !ok {
+		return defaultPath
+	}
+
+	return path
+}
+
+// Set sets a path by name
+func (pc PathsConfig) Set(name, path string) {
+	pc[name] = path
+}
+
+// Has checks if a path exists by name
+func (pc PathsConfig) Has(name string) bool {
+	if pc == nil {
+		return false
+	}
+	_, ok := pc[name]
+	return ok
+}
+
+// EnsureDir ensures a directory exists at the specified path name
+// Creates the directory if it doesn't exist with the given permissions
+func (pc PathsConfig) EnsureDir(name string, perm os.FileMode) error {
+	path, err := pc.Get(name)
+	if err != nil {
+		return err
+	}
+
+	// Check if directory exists
+	info, err := os.Stat(path)
+	if err == nil {
+		// Path exists, check if it's a directory
+		if !info.IsDir() {
+			return fmt.Errorf("path '%s' exists but is not a directory: %s", name, path)
+		}
+		return nil
+	}
+
+	// Directory doesn't exist, create it
+	if os.IsNotExist(err) {
+		if err := os.MkdirAll(path, perm); err != nil {
+			return fmt.Errorf("failed to create directory for '%s' at %s: %w", name, path, err)
+		}
+		return nil
+	}
+
+	return fmt.Errorf("failed to stat path '%s' at %s: %w", name, path, err)
+}
+
+// AbsPath returns the absolute path for a named path
+func (pc PathsConfig) AbsPath(name string) (string, error) {
+	path, err := pc.Get(name)
+	if err != nil {
+		return "", err
+	}
+
+	absPath, err := filepath.Abs(path)
+	if err != nil {
+		return "", fmt.Errorf("failed to get absolute path for '%s': %w", name, err)
+	}
+
+	return absPath, nil
+}
+
+// Join joins path segments with a named base path
+func (pc PathsConfig) Join(name string, elem ...string) (string, error) {
+	base, err := pc.Get(name)
+	if err != nil {
+		return "", err
+	}
+
+	parts := append([]string{base}, elem...)
+	return filepath.Join(parts...), nil
+}
+
+// List returns all configured path names
+func (pc PathsConfig) List() []string {
+	if pc == nil {
+		return []string{}
+	}
+
+	names := make([]string, 0, len(pc))
+	for name := range pc {
+		names = append(names, name)
+	}
+	return names
+}