test(bench): add allocation benchmarks for client/transport/dispatch hot paths

Hermetic benchmarks (no network) covering Call encode+decode, webhook ServeHTTP body parse, and Router dispatch (command/regex/filter). Use Go 1.24+ b.Loop() idiom. .benchstats/baseline.txt pins the pre-optimisation numbers for benchstat comparisons.

dispatch/router_bench_test.go

@@ -0,0 +1,89 @@
+package dispatch
+
+import (
+	"context"
+	"testing"
+
+	"github.com/lukaszraczylo/go-telegram/api"
+	"github.com/lukaszraczylo/go-telegram/client"
+)
+
+func BenchmarkRouter_DispatchCommand(b *testing.B) {
+	r := New(client.New("t"))
+	r.OnCommand("/start", func(c *Context, m *api.Message) error { return nil })
+	u := cmdMessage("/start hello")
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		c := NewContext(ctx, r.bot, &u)
+		_ = r.dispatch(c, &u)
+	}
+}
+
+func BenchmarkRouter_DispatchTextRegex(b *testing.B) {
+	r := New(client.New("t"))
+	r.OnText("^hello.*", func(c *Context, m *api.Message) error { return nil })
+	u := api.Update{
+		UpdateID: 1,
+		Message: &api.Message{
+			MessageID: 1, Date: 0,
+			Chat: api.Chat{ID: 1, Type: api.ChatTypePrivate},
+			Text: "hello world",
+		},
+	}
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		c := NewContext(ctx, r.bot, &u)
+		_ = r.dispatch(c, &u)
+	}
+}
+
+func BenchmarkRouter_DispatchFilter(b *testing.B) {
+	r := New(client.New("t"))
+	r.OnMessageFilter(
+		func(m *api.Message) bool { return m != nil && m.Text == "ping" },
+		func(c *Context, m *api.Message) error { return nil },
+	)
+	u := api.Update{
+		UpdateID: 1,
+		Message: &api.Message{
+			MessageID: 1, Date: 0,
+			Chat: api.Chat{ID: 1, Type: api.ChatTypePrivate},
+			Text: "ping",
+		},
+	}
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		c := NewContext(ctx, r.bot, &u)
+		_ = r.dispatch(c, &u)
+	}
+}
+
+func BenchmarkRouter_NewContext(b *testing.B) {
+	bot := client.New("t")
+	u := &api.Update{UpdateID: 1}
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		_ = NewContext(ctx, bot, u)
+	}
+}
+
+func BenchmarkExtractCommand(b *testing.B) {
+	text := "/start@BotName hello world"
+	cmdLen := len("/start@BotName")
+	m := &api.Message{
+		MessageID: 1, Date: 0,
+		Chat: api.Chat{ID: 1, Type: api.ChatTypePrivate},
+		Text: text,
+		Entities: []api.MessageEntity{
+			{Type: api.MessageEntityTypeBotCommand, Offset: 0, Length: int64(cmdLen)},
+		},
+	}
+	b.ReportAllocs()
+	for b.Loop() {
+		_, _, _ = extractCommand(m)
+	}
+}