refactor: rewrite project from Rust to Go

- Replace Axum with Chi router
- Replace sqlx with pgx for PostgreSQL
- Replace tonic/prost with grpc-go
- Replace tracing with zerolog
- Update flake.nix for Go build with protoc generation
- Preserve all existing endpoints and functionality

Stack: Chi, pgx, grpc-go, zerolog, yaml.v3

internal/indexer/search.go

@@ -0,0 +1,54 @@
+package indexer
+
+import (
+	"regexp"
+	"strings"
+)
+
+type MusicSearchCriteria struct {
+	Artist string
+	Album  *string
+	Year   *uint32
+	Limit  int
+	Offset int
+}
+
+func (c *MusicSearchCriteria) CleanArtist() string {
+	return cleanSearchTerm(c.Artist)
+}
+
+func (c *MusicSearchCriteria) CleanAlbum() *string {
+	if c.Album == nil {
+		return nil
+	}
+	cleaned := cleanSearchTerm(*c.Album)
+	return &cleaned
+}
+
+var cleanRegex = regexp.MustCompile(`[^\w\s]`)
+
+func cleanSearchTerm(s string) string {
+	s = cleanRegex.ReplaceAllString(s, " ")
+	fields := strings.Fields(s)
+	return strings.Join(fields, " ")
+}
+
+type SearchResult struct {
+	GUID        string   `json:"guid"`
+	Title       string   `json:"title"`
+	DownloadURL string   `json:"download_url"`
+	InfoURL     *string  `json:"info_url,omitempty"`
+	Size        uint64   `json:"size"`
+	PublishDate *string  `json:"publish_date,omitempty"`
+	Artist      *string  `json:"artist,omitempty"`
+	Album       *string  `json:"album,omitempty"`
+	Year        *uint32  `json:"year,omitempty"`
+	Label       *string  `json:"label,omitempty"`
+	Seeders     *int     `json:"seeders,omitempty"`
+	Leechers    *int     `json:"leechers,omitempty"`
+	Grabs       *int     `json:"grabs,omitempty"`
+	Infohash    *string  `json:"infohash,omitempty"`
+	MagnetURL   *string  `json:"magnet_url,omitempty"`
+	Indexer     string   `json:"indexer"`
+	Categories  []uint32 `json:"categories"`
+}