internal/divert: embed WinDivert64.sys + WinDivert.dll v2.2.2 with SHA256 sentinels

Adds github.com/imgk/divert-go v0.1.0 dependency. Embedded driver
binaries land at runtime in %PROGRAMDATA%\Drover\windivert\ via the
installer (next task).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/divert/embed.go

@@ -0,0 +1,23 @@
+//go:build windows
+
+package divert
+
+import _ "embed"
+
+//go:embed assets/WinDivert64.sys
+var winDivertSys []byte
+
+//go:embed assets/WinDivert.dll
+var winDivertDll []byte
+
+// Sentinel SHA256 of the embedded binaries — verified on extract.
+// Generated via:
+//
+//   sha256sum internal/divert/assets/WinDivert64.sys
+//   sha256sum internal/divert/assets/WinDivert.dll
+//
+// Update both constants when bumping WinDivert versions.
+const (
+	WinDivertSysSHA256 = "8da085332782708d8767bcace5327a6ec7283c17cfb85e40b03cd2323a90ddc2"
+	WinDivertDllSHA256 = "c1e060ee19444a259b2162f8af0f3fe8c4428a1c6f694dce20de194ac8d7d9a2"
+)