perf(proxy): optimize hot request paths

- Cache route handlers, simplify NoRoute path normalization, and reduce matcher/header allocations

- Honor configured transport pool limits in auto mode and add hotpath regression benchmarks/tests

proxy/httpc_test.go

@@ -0,0 +1,64 @@
+package proxy
+
+import (
+	"ghproxy/config"
+	"testing"
+)
+
+func TestInitHTTPClient_AutoModeUsesConfiguredPoolSizes(t *testing.T) {
+	oldTr, oldClient := tr, client
+	t.Cleanup(func() {
+		tr = oldTr
+		client = oldClient
+	})
+
+	cfg := &config.Config{}
+	cfg.Httpc.Mode = "auto"
+	cfg.Httpc.MaxIdleConns = 123
+	cfg.Httpc.MaxIdleConnsPerHost = 45
+	cfg.Httpc.MaxConnsPerHost = 67
+
+	initHTTPClient(cfg)
+
+	if tr == nil {
+		t.Fatal("transport was not initialized")
+	}
+	if tr.MaxIdleConns != 123 {
+		t.Fatalf("MaxIdleConns = %d, want 123", tr.MaxIdleConns)
+	}
+	if tr.MaxIdleConnsPerHost != 45 {
+		t.Fatalf("MaxIdleConnsPerHost = %d, want 45", tr.MaxIdleConnsPerHost)
+	}
+	if tr.MaxConnsPerHost != 67 {
+		t.Fatalf("MaxConnsPerHost = %d, want 67", tr.MaxConnsPerHost)
+	}
+}
+
+func TestInitGitHTTPClient_AutoModeUsesConfiguredPoolSizes(t *testing.T) {
+	oldGitTr, oldGitClient := gittr, gitclient
+	t.Cleanup(func() {
+		gittr = oldGitTr
+		gitclient = oldGitClient
+	})
+
+	cfg := &config.Config{}
+	cfg.Httpc.Mode = "auto"
+	cfg.Httpc.MaxIdleConns = 98
+	cfg.Httpc.MaxIdleConnsPerHost = 76
+	cfg.Httpc.MaxConnsPerHost = 54
+
+	initGitHTTPClient(cfg)
+
+	if gittr == nil {
+		t.Fatal("git transport was not initialized")
+	}
+	if gittr.MaxIdleConns != 98 {
+		t.Fatalf("MaxIdleConns = %d, want 98", gittr.MaxIdleConns)
+	}
+	if gittr.MaxIdleConnsPerHost != 76 {
+		t.Fatalf("MaxIdleConnsPerHost = %d, want 76", gittr.MaxIdleConnsPerHost)
+	}
+	if gittr.MaxConnsPerHost != 54 {
+		t.Fatalf("MaxConnsPerHost = %d, want 54", gittr.MaxConnsPerHost)
+	}
+}