docs(tests): TEST_CASES.md + wire-tap proof for university practice

Adds proof artifacts that the PQ tunnel is real:

- crates/aura-proto/tests/pq_wire_tap.rs — new integration test that
  intercepts every byte flowing on the in-memory transport and asserts:
  (1) ClientHello payload = 32 + 1184 + 32 (X25519 + ML-KEM-768 ek + nonce),
  (2) ServerHello payload = 32 + 1088 + 32 (X25519_eph + ML-KEM-768 ct + nonce),
  (3) a 56-byte plaintext marker shipped in a Data frame is absent from
      the wire in both directions,
  (4) ServerAuth/Data AEAD bodies have Shannon entropy >= 7 bits/byte.

- TEST_CASES.md — Russian-language report mapping 12 test cases to the
  exact code and captured outputs (KAT, hybrid round-trip, AEAD tamper
  detection, mutual X.509 rejection, replay window, 1000-packet flow,
  in-vivo ping, bench-crypto timings, new wire-tap proof).

- docs/test_evidence/ — full captured stdout of cargo test runs and
  aura bench-crypto, referenced from TEST_CASES.md.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/test_evidence/aura_proto_tests.txt

@@ -0,0 +1,95 @@
+   Compiling aura-proto v0.1.0 (/Users/xah30/AuraVPN/crates/aura-proto)
+    Finished `test` profile [unoptimized + debuginfo] target(s) in 2.37s
+     Running unittests src/lib.rs (target/debug/deps/aura_proto-7edee13b9723a1d1)
+
+running 18 tests
+test frame::tests::control_envelope_rejects_truncated_payload ... ok
+test frame::tests::control_envelope_roundtrip ... ok
+test frame::tests::circuit_failed_envelope_roundtrip ... ok
+test frame::tests::control_envelope_skips_normal_ip_packets ... ok
+test frame::tests::control_envelope_unknown_kind_decodes_as_unknown ... ok
+test frame::tests::control_kind_bytes_stable ... ok
+test frame::tests::extend_bridge_rejects_bad_inputs ... ok
+test frame::tests::extend_bridge_roundtrip_v4_and_v6 ... ok
+test frame::tests::extend_bridge_v4_wire_layout ... ok
+test frame::tests::extend_bridge_v6_wire_layout ... ok
+test frame::tests::frame_decode_rejects_garbage ... ok
+test frame::tests::frame_roundtrip ... ok
+test frame::tests::header_rejects_oversize_and_bad_version ... ok
+test frame::tests::header_roundtrip_all_types ... ok
+test session::tests::replay_window_basic_monotonic ... ok
+test session::tests::replay_window_out_of_order_within_window ... ok
+test session::tests::replay_window_rejects_too_old ... ok
+test session::tests::datagram_roundtrip_reorder_and_replay ... ok
+
+test result: ok. 18 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
+
+     Running tests/control_extend.rs (target/debug/deps/control_extend-290e17e2bf0e7c00)
+
+running 6 tests
+test circuit_failed_carries_utf8_reason ... ok
+test circuit_ready_envelope_has_empty_payload ... ok
+test extend_bridge_payload_roundtrips_ipv4 ... ok
+test extend_bridge_rejects_malformed_payload ... ok
+test extend_bridge_payload_roundtrips_ipv6 ... ok
+test extend_bridge_via_full_envelope ... ok
+
+test result: ok. 6 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
+
+     Running tests/control_frame.rs (target/debug/deps/control_frame-9c0cd4a2cd90b6d1)
+
+running 7 tests
+test control_envelope_magic_does_not_collide_with_ip ... ok
+test control_envelope_rejects_truncated_payload ... ok
+test control_envelope_pass_through_for_non_control_packets ... ok
+test control_envelope_small_roundtrip ... ok
+test control_envelope_unknown_kind_decodes_as_unknown ... ok
+test control_envelope_round_trip_all_kinds ... ok
+test control_envelope_large_payload_roundtrip ... ok
+
+test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.01s
+
+     Running tests/data_exchange.rs (target/debug/deps/data_exchange-66c8285d748033f9)
+
+running 2 tests
+test ping_pong_and_close_frames_roundtrip ... ok
+test test_data_exchange_1000pkts ... ok
+
+test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.11s
+
+     Running tests/handshake_loopback.rs (target/debug/deps/handshake_loopback-13e21367c13bfd93)
+
+running 1 test
+test test_full_handshake_loopback ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.02s
+
+     Running tests/pki_mutual_auth.rs (target/debug/deps/pki_mutual_auth-0f10fd7f46079542)
+
+running 2 tests
+test wrong_ca_client_cert_is_rejected ... ok
+test forged_client_signature_is_rejected ... ok
+
+test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.03s
+
+     Running tests/pq_wire_tap.rs (target/debug/deps/pq_wire_tap-738259f6ef41df6b)
+
+running 2 tests
+test shannon_entropy_baseline ... ok
+test pq_handshake_and_data_wire_capture ... ok
+
+test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.02s
+
+     Running tests/replay_protection.rs (target/debug/deps/replay_protection-e0916aadd85a9593)
+
+running 1 test
+test test_replay_protection ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.02s
+
+   Doc-tests aura_proto
+
+running 0 tests
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
+