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/clips.go

@@ -1,3 +1,4 @@
+// Package client provides methods for interacting with Yandex Music API endpoints.
 package client
 
 import (
@@ -7,7 +8,7 @@ import (
 	"gitea.mrixs.me/Mrixs/yandex-music-api-go/internal/models"
 )
 
-// GetClips gets clips
+// GetClips gets clips with pagination (GET /clips).
 func (c *Client) GetClips(ctx context.Context, page, pageSize int) ([]*models.Clip, error) {
 	params := map[string]string{
 		"page":      "1",
@@ -33,7 +34,7 @@ func (c *Client) GetClips(ctx context.Context, page, pageSize int) ([]*models.Cl
 	return clips, nil
 }
 
-// GetClipsWillLike gets clips the user might like
+// GetClipsWillLike gets clips the user might like (GET /clips/will/like).
 func (c *Client) GetClipsWillLike(ctx context.Context) (*models.ClipsWillLike, error) {
 	var result models.ClipsWillLike
 	if err := c.request.Get(ctx, "/clips/will/like", nil, &result); err != nil {
@@ -42,8 +43,7 @@ func (c *Client) GetClipsWillLike(ctx context.Context) (*models.ClipsWillLike, e
 	return &result, nil
 }
 
-// GetArtistClips gets clips by an artist
-// GET /artists/{artistID}/blocks/artist-clips
+// GetArtistClips gets clips by an artist (GET /artists/{artistID}/blocks/artist-clips).
 func (c *Client) GetArtistClips(ctx context.Context, artistID string) (*models.ArtistClipData, error) {
 	var result models.ArtistClipData
 	if err := c.request.Get(ctx, fmt.Sprintf("/artists/%s/blocks/artist-clips", artistID), nil, &result); err != nil {
@@ -52,7 +52,7 @@ func (c *Client) GetArtistClips(ctx context.Context, artistID string) (*models.A
 	return &result, nil
 }
 
-// GetShots gets shots
+// GetShots gets shots with pagination (GET /shots).
 func (c *Client) GetShots(ctx context.Context, page, pageSize int) ([]*models.Shot, error) {
 	params := map[string]string{
 		"page":      "1",