LazyRun v1.0.0: shortcut maker untuk executable dan PWA

- Fungsi A: shortcut dari file executable (ELF/AppImage/script)
- Fungsi B: shortcut PWA/URL dengan deteksi browser (native, /opt, Flatpak)
- Checkbox Menu Aplikasi / Desktop, desktop-only pakai NoDisplay=true
- List + uninstall + deteksi shortcut yang file .desktop-nya hilang
- Metadata ~/.config/lazyrun/shortcuts.json, refresh cache XDG/KDE
- AppImage + zsync update info via build.sh

internal/icon/favicon.go

@@ -0,0 +1,175 @@
+// Package icon: favicon.go mengambil ikon dari halaman web untuk shortcut PWA.
+package icon
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
+)
+
+var client = &http.Client{Timeout: 8 * time.Second}
+
+// shortcut: parsing HTML pakai regex, bukan parser penuh; cukup untuk tag <link rel=icon>.
+var (
+	linkTag  = regexp.MustCompile(`(?is)<link\b[^>]*>`)
+	relAttr  = regexp.MustCompile(`(?is)\brel\s*=\s*["']?([^"'>]+)`)
+	hrefAttr = regexp.MustCompile(`(?is)\bhref\s*=\s*["']?([^"'\s>]+)`)
+	typeAttr = regexp.MustCompile(`(?is)\btype\s*=\s*["']?([^"'\s>]+)`)
+	sizeAttr = regexp.MustCompile(`(?is)\bsizes\s*=\s*["']?(\d+)`)
+)
+
+// Fetch mengambil favicon dari halaman. Return data + ekstensi file (".png", ".jpg", ".svg").
+func Fetch(pageURL string) ([]byte, string, error) {
+	base, err := url.Parse(pageURL)
+	if err != nil {
+		return nil, "", err
+	}
+
+	var lastErr error
+	for _, candidate := range iconCandidates(base) {
+		data, err := get(candidate)
+		if err != nil {
+			lastErr = err
+			continue
+		}
+		if ext := sniffExt(data); ext != "" {
+			return data, ext, nil
+		}
+		if png := largestPNGFromICO(data); png != nil {
+			return png, ".png", nil
+		}
+		lastErr = errors.New("unsupported icon format at " + candidate)
+	}
+	if lastErr == nil {
+		lastErr = errors.New("no favicon found")
+	}
+	return nil, "", lastErr
+}
+
+// iconCandidate adalah kandidat URL ikon dengan skor prioritas.
+type iconCandidate struct {
+	url   string
+	score int
+}
+
+// iconCandidates mengumpulkan URL ikon dari HTML, ikon besar didahulukan, favicon.ico terakhir.
+func iconCandidates(base *url.URL) []string {
+	var found []iconCandidate
+
+	if page, err := get(base.String()); err == nil {
+		for _, tag := range linkTag.FindAllString(string(page), -1) {
+			rel := strings.ToLower(attr(relAttr, tag))
+			if !strings.Contains(rel, "icon") || strings.Contains(rel, "mask-icon") {
+				continue
+			}
+			href := attr(hrefAttr, tag)
+			if href == "" {
+				continue
+			}
+			ref, err := url.Parse(href)
+			if err != nil {
+				continue
+			}
+			score := 1
+			if strings.Contains(strings.ToLower(attr(typeAttr, tag)), "png") {
+				score += 10
+			}
+			if size := attr(sizeAttr, tag); size != "" {
+				fmt.Sscanf(size, "%d", &score)
+				score += 10
+			}
+			found = append(found, iconCandidate{base.ResolveReference(ref).String(), score})
+		}
+	}
+
+	sort.SliceStable(found, func(i, j int) bool { return found[i].score > found[j].score })
+
+	out := make([]string, 0, len(found)+1)
+	seen := map[string]bool{}
+	for _, c := range found {
+		if !seen[c.url] {
+			seen[c.url] = true
+			out = append(out, c.url)
+		}
+	}
+	fallback := base.ResolveReference(&url.URL{Path: "/favicon.ico"}).String()
+	if !seen[fallback] {
+		out = append(out, fallback)
+	}
+	return out
+}
+
+func attr(re *regexp.Regexp, tag string) string {
+	if m := re.FindStringSubmatch(tag); m != nil {
+		return m[1]
+	}
+	return ""
+}
+
+func get(rawURL string) ([]byte, error) {
+	req, err := http.NewRequest(http.MethodGet, rawURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("User-Agent", "Mozilla/5.0 (X11; Linux x86_64) LazyRun")
+	req.Header.Set("Accept", "text/html,image/*;q=0.9,*/*;q=0.8")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("%s: %s", rawURL, resp.Status)
+	}
+	return io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+}
+
+func sniffExt(data []byte) string {
+	head := data
+	if len(head) > 512 {
+		head = head[:512]
+	}
+	switch {
+	case bytes.HasPrefix(data, []byte("\x89PNG\r\n\x1a\n")):
+		return ".png"
+	case bytes.HasPrefix(data, []byte{0xff, 0xd8, 0xff}):
+		return ".jpg"
+	case bytes.Contains(bytes.ToLower(head), []byte("<svg")):
+		return ".svg"
+	}
+	return ""
+}
+
+// largestPNGFromICO mengambil PNG terbesar di dalam file .ico.
+// ICO dari BMP lama tidak didukung (langka untuk favicon).
+func largestPNGFromICO(data []byte) []byte {
+	if len(data) < 22 || data[0] != 0 || data[1] != 0 || data[2] != 1 || data[3] != 0 {
+		return nil
+	}
+	count := int(data[4]) | int(data[5])<<8
+	var best []byte
+	for i := 0; i < count; i++ {
+		off := 6 + i*16
+		if off+16 > len(data) {
+			break
+		}
+		size := int(data[off+8]) | int(data[off+9])<<8 | int(data[off+10])<<16 | int(data[off+11])<<24
+		start := int(data[off+12]) | int(data[off+13])<<8 | int(data[off+14])<<16 | int(data[off+15])<<24
+		if size <= 0 || start < 0 || start+size > len(data) {
+			continue
+		}
+		blob := data[start : start+size]
+		if bytes.HasPrefix(blob, []byte("\x89PNG\r\n\x1a\n")) && len(blob) > len(best) {
+			best = blob
+		}
+	}
+	return best
+}