[AZ-615] [AZ-617] Add Jetson e2e harness + tier2 marks

C7 inference (PytorchFp16Runtime / TensorRTRuntime / OnnxTrtEpRuntime)
is CUDA-only by design — `model.half().cuda()` is hard-wired with no
CPU fallback. The Colima/Tier-1 smoke harness can never exercise C3
matcher or C7 inference. Once AZ-614 fixes the tlog time-base mismatch
and the pipeline reaches those stages, Colima runs would hard-fail at
`.cuda()` instead of cleanly skipping.

This commit lays down the Jetson companion harness and wires the
existing `tier2` auto-skip:

  * tests/e2e/Dockerfile.jetson  — l4t-pytorch:r36.4.0-pth2.3-py3 base,
    same /opt layout as the Colima image so AC-4 AST scan + bind mounts
    work identically. Built ON the Jetson via run-tests-jetson.sh.
  * docker-compose.test.jetson.yml — mirrors docker-compose.test.yml
    but with `runtime: nvidia`, GPU device exposure, and
    GPS_DENIED_TIER=2 (turns OFF the tier2 auto-skip).
  * scripts/run-tests-jetson.sh — rsync → ssh build → ssh up,
    exit-code-from e2e-runner so the local exit code reflects the
    remote test verdict. No credentials in the repo; uses
    `ssh jetson-e2e` alias resolved via ~/.ssh/config.
  * _docs/03_implementation/jetson_harness_setup.md — one-time SSH
    key + alias + sshd hardening + GPU verification steps. Documents
    the smoke vs. Reality Gate split + the GPS_DENIED_TIER switch.

AZ-617 (mark heavy ACs with tier2): adds @pytest.mark.tier2 to AC-1,
AC-2, AC-3, AC-5, AC-6 in tests/e2e/replay/test_derkachi_1min.py.
Reuses the existing tier2 marker + auto-skip in tests/conftest.py
(scope revision documented as a comment on AZ-617). AC-4a/4b/AC-7/AC-9
stay unmarked — they don't touch CUDA.

Defers to follow-up Jira:

  * AZ-614 — Derkachi tlog synth time-base mismatch (unblocks tier2 ACs
    actually reaching the GPU stage on the Jetson)
  * AZ-616 — replace mock-sat with real ../satellite-provider service

Not run yet: the harness needs operator-side SSH setup to come online
before scripts/run-tests-jetson.sh can be executed end-to-end. Setup
steps documented in jetson_harness_setup.md.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/e2e/replay/test_derkachi_1min.py

@@ -56,6 +56,7 @@ _HEAVY_SKIP = pytest.mark.skipif(
 # AC-1: CLI exits 0; JSONL line count matches tlog GLOBAL_POSITION_INT count
 
 
+@pytest.mark.tier2
 @_HEAVY_SKIP
 def test_ac1_exits_0_jsonl_count_match(replay_runner, derkachi_replay_inputs) -> None:
     # Act
@@ -97,6 +98,7 @@ _ESTIMATOR_OUTPUT_KEYS = frozenset(
 )
 
 
+@pytest.mark.tier2
 @_HEAVY_SKIP
 def test_ac2_jsonl_schema_match(replay_runner) -> None:
     # Act
@@ -121,6 +123,7 @@ def test_ac2_jsonl_schema_match(replay_runner) -> None:
 # AC-3: ≥ 80 % of emissions within 100 m of ground truth
 
 
+@pytest.mark.tier2
 @_HEAVY_SKIP
 @pytest.mark.xfail(
     reason=(
@@ -350,6 +353,7 @@ def test_ac4_encoder_byte_equality_via_transport_seam() -> None:
 # AC-5: Determinism (two runs differ by ≤ 1e-6 in position fields)
 
 
+@pytest.mark.tier2
 @_HEAVY_SKIP
 def test_ac5_determinism_two_runs_diff(replay_runner) -> None:
     # Act
@@ -378,6 +382,7 @@ def test_ac5_determinism_two_runs_diff(replay_runner) -> None:
 # AC-6: Pace timing
 
 
+@pytest.mark.tier2
 @_HEAVY_SKIP
 def test_ac6_pace_realtime_60s_within_5pct(replay_runner) -> None:
     # Act
@@ -391,6 +396,7 @@ def test_ac6_pace_realtime_60s_within_5pct(replay_runner) -> None:
     )
 
 
+@pytest.mark.tier2
 @_HEAVY_SKIP
 def test_ac6_pace_asap_under_30s(replay_runner) -> None:
     # Act