Decompose Step 6 snapshot: 140 task specs + contract docs

Closes out greenfield Step 6 (Decompose) for all 14 components
(C1-C13 + cross-cutting helpers/replay). Covers tasks AZ-266..AZ-446
plus the _dependencies_table.md and component contract documents.

State file updated to greenfield Step 7 (Implement), not_started.

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

_docs/02_tasks/todo/AZ-444_tier2_jetson_harness.md

@@ -0,0 +1,78 @@
+# Tier-2 Jetson harness wrapper
+
+**Task**: AZ-444_tier2_jetson_harness
+**Name**: Tier-2 hardware-loop runner — `run-tier2.sh`, ssh provisioning, systemd service install, ASan-fuzz mode, image-flash automation
+**Description**: Implement the Tier-2 hardware-loop wrapper that AZ-406 stubs out — actual ssh-based runner, systemd service install for SUT on Jetson, `tegrastats` capture, ASan-fuzz launch path.
+**Complexity**: 5 points
+**Dependencies**: AZ-406
+**Component**: Blackbox Tests / Tier-2 runner (epic AZ-262)
+**Tracker**: AZ-444
+**Epic**: AZ-262 (E-BBT)
+
+## Problem
+
+AZ-406 scaffolds Tier-2 (`run-tier2.sh` exists as a stub); but the actual hardware-loop semantics — ssh provisioning, image-flash automation, systemd service-life management, telemetry capture, ASan-fuzz launch — are non-trivial and need a dedicated task.
+
+## Outcome
+
+- `e2e/tier2/run-tier2.sh` accepts the same `pytest -k <selector>` selector as Tier-1 and runs the selector against a configured Jetson host (env var `TIER2_HOST`).
+- Provisioning: ssh-based; runs `apt update && apt install -y ...` for runner deps if not already present (idempotent).
+- SUT lifecycle: installs the SUT as a systemd service (`gps-denied-onboard.service`); restart command is `systemctl restart gps-denied-onboard`.
+- Telemetry capture: `tegrastats` runs as a parallel ssh stream during each test; output piped into the per-run evidence bundle.
+- ASan-fuzz: separate `--build-kind asan` mode that flashes the ASan image (or builds it remotely) and runs the fuzz binary with stderr captured.
+- Image-flash automation: `--reflash` flag (gated, OFF by default) re-flashes the Jetson via `nvidia-sdkmanager-cli` when needed.
+
+## Scope
+
+### Included
+- `run-tier2.sh` runner.
+- ssh-based provisioning + systemd install/restart.
+- `tegrastats` parallel capture.
+- ASan-fuzz launch.
+- Image-flash automation (gated).
+
+### Excluded
+- The CSV reporter — owned by AZ-406.
+- Per-scenario test logic — owned by individual scenario tasks.
+- Chamber automation for +50 °C — out of scope.
+
+## Acceptance Criteria
+
+**AC-1: selector parity**
+Given the same `pytest -k <selector>` invocation
+Then both `run-tier1.sh` and `run-tier2.sh` accept it; the resulting test selection on Tier-2 is the same as Tier-1 (modulo `tier == tier2-jetson` skip rules).
+
+**AC-2: idempotent provisioning**
+Given the Jetson host has the runner deps already installed
+When `run-tier2.sh` runs
+Then provisioning is a no-op (idempotent).
+
+**AC-3: systemd lifecycle**
+Given a Tier-2 test triggers `restart`
+Then `systemctl restart gps-denied-onboard` is issued; the SUT process restarts within ≤5 s.
+
+**AC-4: tegrastats parallel capture**
+Given any Tier-2 test
+Then `tegrastats` runs as a parallel ssh stream during the test; its output lands in `e2e-results/run-${RUN_ID}/tegrastats-${tier2-host}-${test_id}.log`.
+
+**AC-5: ASan-fuzz mode**
+Given `--build-kind asan` flag
+Then the runner ensures the ASan SUT image is installed; the fuzz binary is launched; stderr is captured into `e2e-results/run-${RUN_ID}/asan-fuzz-${test_id}.log`.
+
+**AC-6: image-flash gating**
+Given the `--reflash` flag is OFF (default)
+Then image-flash is NOT triggered; the runner errors out with a clear message if the on-Jetson SUT version does not match the test selection's expected version.
+
+## System Under Test Boundary
+
+This task IS infrastructure — no SUT logic is exercised by it. The Tier-2 harness only orchestrates SUT lifecycle on real hardware.
+
+## Constraints
+
+- ssh-based: requires `TIER2_HOST` + `TIER2_USER` + `TIER2_KEY_PATH` env vars; fails fast if any are missing.
+- The reflash path uses NVIDIA's `sdkmanager-cli` and is environment-specific; it is gated OFF by default to prevent accidental hardware re-provisioning during routine CI.
+
+## Document Dependencies
+
+- `_docs/02_document/tests/environment.md` § Tier-2 (Jetson hardware loop)
+- `_docs/02_document/tests/test-data.md` § Tier-2-only fixtures (none beyond shared)