feat(tui): NVIDIA SAT with nvtop, GPU selection, metrics and chart — v1.0.0

- TUI: duration presets (10m/1h/8h/24h), GPU multi-select checkboxes
- nvtop launched concurrently with SAT via tea.ExecProcess; can reopen or abort
- GPU metrics collected per-second during bee-gpu-stress (temp/usage/power/clock)
- Outputs: gpu-metrics.csv, gpu-metrics.html (offline SVG), gpu-metrics-term.txt
- Terminal chart: asciigraph-style line chart with box-drawing chars and ANSI colours
- AUDIT_VERSION bumped 0.1.1 → 1.0.0; nvtop added to ISO package list
- runtime-flows.md updated with full NVIDIA SAT TUI flow documentation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible-local/architecture/runtime-flows.md

@@ -140,3 +140,34 @@ Acceptance flows:
   - `BEE_GPU_STRESS_SIZE_MB`
   - `BEE_MEMTESTER_SIZE_MB`
   - `BEE_MEMTESTER_PASSES`
+
+## NVIDIA SAT TUI flow (v1.0.0+)
+
+```
+TUI: Acceptance tests → NVIDIA command pack
+  1. screenNvidiaSATSetup
+       a. enumerate GPUs via `nvidia-smi --query-gpu=index,name,memory.total`
+       b. user selects duration preset: 10 min / 1 h / 8 h / 24 h
+       c. user selects GPUs via checkboxes (all selected by default)
+       d. memory size = max(selected GPU memory) — auto-detected, not exposed to user
+  2. Start → screenNvidiaSATRunning
+       a. CUDA_VISIBLE_DEVICES set to selected GPU indices
+       b. tea.Batch: SAT goroutine + tea.ExecProcess(nvtop) launched concurrently
+       c. nvtop occupies full terminal; SAT result queues in background
+       d. [o] reopen nvtop at any time; [a] abort (cancels context → kills bee-gpu-stress)
+  3. GPU metrics collection (during bee-gpu-stress)
+       - background goroutine polls `nvidia-smi` every second
+       - per-second rows: elapsed, GPU index, temp°C, usage%, power W, clock MHz
+       - outputs: gpu-metrics.csv, gpu-metrics.html (offline SVG chart), gpu-metrics-term.txt
+  4. After SAT completes
+       - result shown in screenOutput with terminal line-chart (gpu-metrics-term.txt)
+       - chart is asciigraph-style: box-drawing chars (╭╮╰╯─│), 4 series per GPU,
+         Y axis with ticks, ANSI colours (red=temp, blue=usage, green=power, yellow=clock)
+```
+
+**Critical invariants:**
+- `nvtop` must be in `iso/builder/config/package-lists/bee.list.chroot` (baked into ISO).
+- `bee-gpu-stress` uses `exec.CommandContext` — aborted on cancel.
+- Metric goroutine uses stopCh/doneCh pattern; main goroutine waits `<-doneCh` before reading rows (no mutex needed).
+- If `nvtop` is not found on PATH, SAT still runs without it (graceful degradation).
+- SVG chart is fully offline: no JS, no external CSS, pure inline SVG.