clean up docs/comments

.env.template

···
-CLIENT_ID=
-CLIENT_SECRET=
-REDIRECT_URL=
+# Server configuration
+SERVER_PORT=8080
+SERVER_HOST=localhost
+
+# Spotify OAuth configuration
+SPOTIFY_CLIENT_ID=
+SPOTIFY_CLIENT_SECRET=
+SPOTIFY_AUTH_URL=https://accounts.spotify.com/authorize
+SPOTIFY_TOKEN_URL=https://accounts.spotify.com/api/token
+SPOTIFY_SCOPES=user-read-currently-playing user-read-email
+
+# Callback URLs
+CALLBACK_SPOTIFY=http://localhost:8080/callback/spotify
+
+# Tracker settings
+TRACKER_INTERVAL=30
+
+# Database settings
+DB_PATH=./piper.db

README.md

···
 ```
 air
 ```
+
+air should automatically build and run piper, and watch for changes on relevant files.
+
+#### docker
+
+TODO

oauth/oauth2.go

···
 	"golang.org/x/oauth2/spotify"
 )
 
-// OAuth2Service represents an OAuth2 service with PKCE support
 type OAuth2Service struct {
 	config        oauth2.Config
 	state         string
···
 	codeChallenge string
 }
 
-// generateRandomState creates a random state string for CSRF protection
 func generateRandomState() string {
 	b := make([]byte, 16)
 	rand.Read(b)
···
 func NewOAuth2Service(clientID, clientSecret, redirectURI string, scopes []string, provider string) *OAuth2Service {
 	var endpoint oauth2.Endpoint
 
-	// Select the appropriate provider endpoint
 	switch strings.ToLower(provider) {
 	case "spotify":
 		endpoint = spotify.Endpoint
 	default:
-		// Use custom endpoints if not a predefined provider
+		// TODO: support custom endpoints plus lastfm
 		endpoint = oauth2.Endpoint{
 			AuthURL:  "https://example.com/auth",
 			TokenURL: "https://example.com/token",

oauth/oauth_manager.go

···
 	SetAccessToken(token string) int64
 }
 
-// OAuthServiceManager manages multiple OAuth services
+// manages multiple oauth2 client services
 type OAuthServiceManager struct {
 	oauth2Services map[string]*OAuth2Service
 	sessionManager *session.SessionManager
 	mu             sync.RWMutex
 }
 
-// NewOAuthServiceManager creates a new OAuthServiceManager
 func NewOAuthServiceManager() *OAuthServiceManager {
 	return &OAuthServiceManager{
 		oauth2Services: make(map[string]*OAuth2Service),
···
 	}
 }
 
-// RegisterOAuth2Service adds a new OAuth2 service with PKCE to the manager
 func (m *OAuthServiceManager) RegisterOAuth2Service(name string, service *OAuth2Service) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	m.oauth2Services[name] = service
 }
 
-// GetOAuth2Service retrieves an OAuth2 service by name
 func (m *OAuthServiceManager) GetOAuth2Service(name string) (*OAuth2Service, bool) {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
···
 	return service, exists
 }
 
-// HandleLogin creates a handler for the login endpoint for a specific service
 func (m *OAuthServiceManager) HandleLogin(serviceName string) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		m.mu.RLock()
···
 	}
 }
 
-// HandleCallback creates a handler for the callback endpoint for a specific service
 func (m *OAuthServiceManager) HandleCallback(serviceName string, tokenReceiver TokenReceiver) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		m.mu.RLock()

service/spotify/playlists.go

···
 }
 
 func (s *SpotifyService) getUserPlaylists(userID int64) (*PlaylistResponse, error) {
-
 	s.mu.RLock()
 	token, exists := s.userTokens[userID]
 	s.mu.RUnlock()