Add comprehensive godoc documentation to all exported symbols

- Document all exported types, functions, methods, and constants across 52 files
- Add package-level doc comments to client, models, utils, and ynison packages
- Document HTTP method and endpoint path for each API client method
- Document model struct fields and DeJSON/DeList/ToJSON/ToMap methods
- Fix duplicate package doc comment in internal/models/base.go

Co-Authored-By: Claude Code <noreply@anthropic.com>

internal/client/search.go

@@ -1,3 +1,4 @@
+// Package client provides methods for interacting with Yandex Music API endpoints.
 package client
 
 import (
@@ -7,7 +8,8 @@ import (
 	"gitea.mrixs.me/Mrixs/yandex-music-api-go/internal/models"
 )
 
-// Search performs a multi-type search
+// Search performs a multi-type search (GET /search).
+// The searchType parameter specifies what to search for (e.g., "track", "album", "artist").
 func (c *Client) Search(ctx context.Context, query string, searchType string, page, pageSize int) (*models.SearchResult, error) {
 	params := map[string]string{
 		"text":      query,
@@ -46,7 +48,7 @@ func (c *Client) Search(ctx context.Context, query string, searchType string, pa
 	return &result, nil
 }
 
-// SearchTracks searches for tracks
+// SearchTracks searches for tracks using Search with type "track".
 func (c *Client) SearchTracks(ctx context.Context, query string, page, pageSize int) (*models.SearchTracksResult, error) {
 	result, err := c.Search(ctx, query, "track", page, pageSize)
 	if err != nil {
@@ -55,7 +57,7 @@ func (c *Client) SearchTracks(ctx context.Context, query string, page, pageSize
 	return result.Tracks, nil
 }
 
-// SearchAlbums searches for albums
+// SearchAlbums searches for albums using Search with type "album".
 func (c *Client) SearchAlbums(ctx context.Context, query string, page, pageSize int) (*models.SearchAlbumsResult, error) {
 	result, err := c.Search(ctx, query, "album", page, pageSize)
 	if err != nil {
@@ -64,7 +66,7 @@ func (c *Client) SearchAlbums(ctx context.Context, query string, page, pageSize
 	return result.Albums, nil
 }
 
-// SearchArtists searches for artists
+// SearchArtists searches for artists using Search with type "artist".
 func (c *Client) SearchArtists(ctx context.Context, query string, page, pageSize int) (*models.SearchArtistsResult, error) {
 	result, err := c.Search(ctx, query, "artist", page, pageSize)
 	if err != nil {
@@ -73,7 +75,7 @@ func (c *Client) SearchArtists(ctx context.Context, query string, page, pageSize
 	return result.Artists, nil
 }
 
-// SearchPlaylists searches for playlists
+// SearchPlaylists searches for playlists using Search with type "playlist".
 func (c *Client) SearchPlaylists(ctx context.Context, query string, page, pageSize int) (*models.SearchPlaylistsResult, error) {
 	result, err := c.Search(ctx, query, "playlist", page, pageSize)
 	if err != nil {
@@ -82,7 +84,7 @@ func (c *Client) SearchPlaylists(ctx context.Context, query string, page, pageSi
 	return result.Playlists, nil
 }
 
-// SearchVideos searches for videos
+// SearchVideos searches for videos using Search with type "video".
 func (c *Client) SearchVideos(ctx context.Context, query string, page, pageSize int) (*models.SearchVideosResult, error) {
 	result, err := c.Search(ctx, query, "video", page, pageSize)
 	if err != nil {
@@ -91,7 +93,7 @@ func (c *Client) SearchVideos(ctx context.Context, query string, page, pageSize
 	return result.Videos, nil
 }
 
-// SearchUsers searches for users
+// SearchUsers searches for users using Search with type "user".
 func (c *Client) SearchUsers(ctx context.Context, query string, page, pageSize int) (*models.SearchUsersResult, error) {
 	result, err := c.Search(ctx, query, "user", page, pageSize)
 	if err != nil {
@@ -100,7 +102,7 @@ func (c *Client) SearchUsers(ctx context.Context, query string, page, pageSize i
 	return result.Users, nil
 }
 
-// SearchSuggestions gets search suggestions
+// SearchSuggestions gets search suggestions for a query (GET /search/suggest?type=suggest).
 func (c *Client) SearchSuggestions(ctx context.Context, query string) ([]string, error) {
 	params := map[string]string{
 		"text": query,
@@ -116,7 +118,7 @@ func (c *Client) SearchSuggestions(ctx context.Context, query string) ([]string,
 	return result.Suggestions, nil
 }
 
-// SearchBanners gets search banners
+// SearchBanners gets search banners for a query (GET /search/banner?type=banner).
 func (c *Client) SearchBanners(ctx context.Context, query string) ([]models.SearchBanner, error) {
 	params := map[string]string{
 		"text": query,
@@ -132,7 +134,7 @@ func (c *Client) SearchBanners(ctx context.Context, query string) ([]models.Sear
 	return result.Banners, nil
 }
 
-// SearchTags gets search tags
+// SearchTags gets search tags for a query (GET /search/tag?type=tag).
 func (c *Client) SearchTags(ctx context.Context, query string) ([]models.Tag, error) {
 	params := map[string]string{
 		"text": query,