fix: fetcher proxy support, Dockerfile sing-box, rename index format

1. sslinks 403: Cloudflare blocks server IP. Add fetcher.proxy_url config
   so subscription/flow requests can route through an HTTP proxy.

2. Egress probe: Docker image lacked sing-box. Install sing-box v1.11.4
   in the Alpine runtime stage.

3. Collection rename: group by display baseName instead of internal
   groupKey, format index as -N instead of %02d. Fixes double-suffix
   issue where EnsureUniqueProxyNames appended -2/-3 onto existing  02.

internal/filter/collection_rename.go

@@ -30,14 +30,17 @@ func resolveRenameOptions(opts *model.RenameOptions) model.RenameOptions {
 
 // RenameCollectionNodes renames proxy nodes in the collection-level format:
 //
-//	[emoji country flag] [alias] [country name] [city] [01...100]
+//	[emoji country flag] [alias] [country name] [city] [-1...-N]
 //
 // The alias is read from each node's "_sourceAlias" field (tagged by the
 // subscription service from the source's Alias). Geographic info (flag,
 // country, city) is auto-detected from the node's original name and server.
-// Nodes are grouped by country+city+alias and numbered sequentially within
-// each group, starting at 01. If only one node exists in a group, no number
-// is appended.
+//
+// Nodes are grouped by their **display baseName** (the name without the index
+// suffix) and numbered sequentially within each group, starting at 1. This
+// ensures that nodes producing the same display name get unique suffixes
+// (-1, -2, -3, …) in a single pass, so EnsureUniqueProxyNames never needs to
+// append a secondary suffix.
 //
 // opts controls which fields are included in the output. A nil opts means all
 // fields are included (full default format).
@@ -48,19 +51,16 @@ func RenameCollectionNodes(proxies []model.ProxyNode, opts *model.RenameOptions)
 
 	o := resolveRenameOptions(opts)
 
-	type groupKey struct {
-		alias   string
-		country string
-		city    string
+	// First pass: compute display baseName (without index) for each node.
+	type nodeInfo struct {
+		proxy    model.ProxyNode
+		baseName string // display name without index suffix; "" means skip rename
 	}
 
-	groups := make(map[groupKey]int)
-	results := make([]model.ProxyNode, len(proxies))
-
-	// First pass: count group sizes
+	infos := make([]nodeInfo, len(proxies))
 	for i, proxy := range proxies {
 		if proxy == nil {
-			results[i] = proxy
+			infos[i] = nodeInfo{proxy: proxy}
 			continue
 		}
 
@@ -70,45 +70,10 @@ func RenameCollectionNodes(proxies []model.ProxyNode, opts *model.RenameOptions)
 
 		geo := util.DetectGeoWithServer(name, server)
 		if geo.CountryName == "" {
-			results[i] = proxy
+			infos[i] = nodeInfo{proxy: proxy}
 			continue
 		}
 
-		key := groupKey{
-			alias:   alias,
-			country: geo.CountryCN,
-			city:    geo.CityCN,
-		}
-		groups[key]++
-	}
-
-	// Second pass: assign names with numbering
-	counters := make(map[groupKey]int)
-	for i, proxy := range proxies {
-		if proxy == nil {
-			continue
-		}
-
-		name := ToString(proxy["name"])
-		alias := ToString(proxy["_sourceAlias"])
-		server := ToString(proxy["server"])
-
-		geo := util.DetectGeoWithServer(name, server)
-		if geo.CountryName == "" {
-			results[i] = proxy
-			continue
-		}
-
-		key := groupKey{
-			alias:   alias,
-			country: geo.CountryCN,
-			city:    geo.CityCN,
-		}
-
-		counters[key]++
-		total := groups[key]
-
-		// Build name parts based on enabled options
 		var parts []string
 
 		if o.Flag && geo.Flag != "" {
@@ -131,15 +96,45 @@ func RenameCollectionNodes(proxies []model.ProxyNode, opts *model.RenameOptions)
 			parts = append(parts, geo.CityCN)
 		}
 
-		baseName := strings.Join(parts, " ")
+		infos[i] = nodeInfo{
+			proxy:    proxy,
+			baseName: strings.Join(parts, " "),
+		}
+	}
 
-		if o.Index && total > 1 {
-			baseName = fmt.Sprintf("%s %02d", baseName, counters[key])
+	// Count group sizes by baseName.
+	baseCounts := make(map[string]int)
+	for _, info := range infos {
+		if info.baseName != "" {
+			baseCounts[info.baseName]++
+		}
+	}
+
+	// Second pass: assign names with sequential numbering.
+	counters := make(map[string]int)
+	results := make([]model.ProxyNode, len(proxies))
+	for i, info := range infos {
+		if info.proxy == nil {
+			results[i] = info.proxy
+			continue
+		}
+		if info.baseName == "" {
+			// Geo detection failed — keep original name.
+			results[i] = info.proxy
+			continue
 		}
 
-		next := cloneProxy(proxy)
+		counters[info.baseName]++
+		total := baseCounts[info.baseName]
+
+		name := info.baseName
+		if o.Index && total > 1 {
+			name = fmt.Sprintf("%s-%d", name, counters[info.baseName])
+		}
+
+		next := cloneProxy(info.proxy)
 		delete(next, "_sourceAlias")
-		next["name"] = baseName
+		next["name"] = name
 		results[i] = next
 	}
 

internal/filter/collection_rename_test.go

@@ -45,10 +45,10 @@ func TestRenameCollectionNodes_MultipleNodes(t *testing.T) {
 	if len(result) != 3 {
 		t.Fatalf("expected 3 nodes, got %d", len(result))
 	}
-	// All 3 should be numbered 01, 02, 03
+	// All 3 should be numbered -1, -2, -3
 	for i, node := range result {
 		name := node["name"].(string)
-		expected := fmt.Sprintf("%02d", i+1)
+		expected := fmt.Sprintf("-%d", i+1)
 		if !strings.Contains(name, expected) {
 			t.Errorf("node[%d]: expected number %s in name %q", i, expected, name)
 		}
@@ -222,7 +222,7 @@ func TestRenameCollectionNodes_DisableIndex(t *testing.T) {
 	for i, node := range result {
 		name := node["name"].(string)
 		// Should not contain number suffix
-		suffix := fmt.Sprintf("%02d", i+1)
+		suffix := fmt.Sprintf("-%d", i+1)
 		if strings.HasSuffix(name, suffix) {
 			t.Errorf("node[%d]: index should be disabled, got %q", i, name)
 		}
@@ -247,7 +247,7 @@ func TestRenameCollectionNodes_OnlyFlagAndIndex(t *testing.T) {
 		if strings.Contains(name, "[A]") {
 			t.Errorf("node[%d]: alias should not appear, got %q", i, name)
 		}
-		expected := fmt.Sprintf("🇭🇰 %02d", i+1)
+		expected := fmt.Sprintf("🇭🇰-%d", i+1)
 		if name != expected {
 			t.Errorf("node[%d]: expected %q, got %q", i, expected, name)
 		}