feat(nfc): Poll the NFC tag through the soak instead of sampling it once

nfc_polling.sh wraps blantons_nfc_validate.py in a background loop and
keeps score: start/stop/status/tail/report/clear/fg. Script A takes a
30s baseline, Script B starts the poll for the soak, Script C stops it
with the other monitors and reports.

report only reads the log, so it can be run mid-soak without disturbing
anything - and it says RUNNING so a snapshot is not read as the final
answer. Each round appends a machine-readable RESULT line, which keeps
the tally independent of the tool's wording.

ERROR is counted apart from FAIL. A round where the tool printed neither
[PASS] nor [FAIL] - crashed, missing, hung past the timeout - measured
nothing, and that is a different fault from a tag that would not read.
Rolling them together hides whichever one you are not looking for.

Two habits from earlier bugs are baked in: tail does not follow (tail -f
never returns and a macro waiting on the prompt hangs there), and the .py
is called through python3 rather than ./ (it arrives mode 100644 and a
USB copy carries no execute bit).

Also fixes Script C copying "nfc_polling.log" to the job dir when the
file is "nfc_poll.log". The cp failed, nothing checked it, and the run
finished looking fine - you would find out at the desk, with a job
archive that had no NFC log in it.

Script A -> V1.1.2.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014RetWKFZFG1ZHcitQAyhwM

CLAUDE.md

@@ -9,7 +9,7 @@ DUT 端的取數能力由一組 **bash 工具庫** 提供（CB FPGA `pcimem` →
 
 完整架構見 [ARCHITECTURE.md](ARCHITECTURE.md)。
 
-**目前狀態（2026-08-28）**：Script A 為 **V1.1.1**（A 集中記錄 A/B/C 三支的變更）。涵蓋
+**目前狀態（2026-08-28）**：Script A 為 **V1.1.2**（A 集中記錄 A/B/C 三支的變更）。涵蓋
 PCIe AER / DDR EDAC / PMON+TPM / 電壓 margin（9 顆 LTC2980）/ SWB loopback 線速流量 /
 10G+1G 管理網路 ping / BMC DDR 與 USB / NVMe 健康，壓力層走平台的 `bgctl`。
 switch unit 數量由 `config.ttl` 的 `SWB_UNIT0` / `SWB_UNIT1` 宣告，風扇轉速由 `FAN_SPEED` 指定
@@ -22,7 +22,8 @@ TR518 負載（`blanton_tr518.sh`，**TTL 尚未接**）、SWB 軌功耗（`TH6_
 線速流量也納入 100G `ce0`（VLAN 138，靠 ingress mirror 維持循環）。
 Script A 開頭會先收掉前一輪殘留（`hw-test-session finish` + `bgctl reset/stop --all`），
 再 `bgctl list` 確認沒有 job 留著佔資源。
-最後一次發布是 **V1.1.0**；SWB 的 I2C 通道與位址已於 2026-08-19 上機驗證。
+NFC tag 讀取由 `nfc_polling.sh` 背景輪詢（A 做基線、B 起、C 停並 report）。
+最後一次發布是 **V1.1.1**；SWB 的 I2C 通道與位址已於 2026-08-19 上機驗證。
 交付用 `./publish/publish.sh` 打包。
 
 ## 技術棧
@@ -129,6 +130,16 @@ sleep 30                                      # 至少等一個 interval 再 rep
 ./Blanton_Script/blanton_tr518.sh stop        # 只送 port cd lb=none
 #   ⚠️ stop 不還原 l2 learn / test mode（TR_RESTORE_LEARN=1 / _TESTMODE=1 才會）
 
+# ── NFC tag 輪詢 ────────────────────────────────────
+~/Blanton_Script/nfc_polling.sh start      # 背景，start 會先清空 log
+~/Blanton_Script/nfc_polling.sh status     # pid、已跑幾輪、最後一筆結果
+~/Blanton_Script/nfc_polling.sh report     # PASS/FAIL/ERROR 統計，polling 中也能跑
+~/Blanton_Script/nfc_polling.sh tail 50    # 最後 50 行（不 follow，不會卡住）
+~/Blanton_Script/nfc_polling.sh stop
+#   log: ~/Blanton_Script/log/nfc_poll.log
+#   ERROR = 工具沒印出 [PASS]/[FAIL]（或逾時），跟「tag 讀不到」分開算
+#   NFC_INTERVAL_SEC / NFC_TIMEOUT_SEC / NFC_ARGS 可調（要每個子指令都帶）
+
 # ── USB 目標偵測 ────────────────────────────────────
 bash ~/Blanton_Script/usb_target.sh -o dev              # /dev/sdX1
 bash ~/Blanton_Script/usb_target.sh -o mnt              # 掛好並回傳掛載點