Add hall sensor circuit design, NTAG5 config check tool, I2C bus docs

- Hall sensor + LP5562 EN wired-AND circuit design (DRV5032FB/FE,
  1M pull-up, open-drain topology) with three interaction modes:
  boot-time recovery, tap-to-swap, hold-to-confirm recovery
- NTAG5 config check tool (tools/ntag5_config_check.py) using
  uFCoder library for ISO15693 transparent mode via uFR Zero reader.
  Supports inventory + addressed mode for multi-tag fields.
- Updated DEVELOPMENT_PLAN with I2C bus management notes for
  LP5562 (0x30) + NTAG5Link (0x54) shared bus
- Updated README with wired-AND hardware diagram, hall sensor
  interaction section, and updated wiring table
- Updated CLAUDE.md with LP5562 EN wired-AND topology docs
- Updated STATUS.md with hall sensor decisions and hardware inventory

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

docs/STATUS.md

@@ -131,6 +131,9 @@
 | Firmware update strategy | Deferred | UF2 for dev, NFC OTA evaluated later |
 | NTAG5Link I2C slave address | Assumed 0x54 | Verify in M4 with Click board |
 | Pattern binary format | Deferred to M5 | Design after M2-M3 engine experience |
+| Hall sensor + EN circuit | Designed | Wired-AND: hall + MCU open-drain on EN with 1M pull-up. See `docs/plans/2026-03-03-hall-en-design.md` |
+| Hall sensor part selection | Decided | DRV5032FB (SOT-23, 8.4mT, prototype) → DRV5032FE (X2SON 1x1mm, final PCB) |
+| EN pull-up value | Decided | 1M — zero steady-state draw, 3µA when EN low, ~10µs rise time |
 
 ## Hardware Inventory
 
@@ -140,6 +143,6 @@
 | LP5562EVM | Available | TI eval module, RGBW LEDs, I2C addr 0x30 |
 | Mini-USB cable | Not on hand | Needed to flash XIAO M0 |
 | NTAG5 Link Click | Available, partially wired | Missing I2C jumper to XIAO |
-| Hall effect sensor | Not available | Need to source |
+| Hall effect sensor | Not available | Need to source — TI DRV5032FB (SOT-23) for prototype |
 | ACR1552 PCSC reader | Available | For ntag5sensor Python tooling |
 | Multimeter | Available | For power budget measurements |