Record the 2026-09-05 UM FeatherS3 rewire sheet in docs/HARDWARE.md #282

What

Copy the UM FeatherS3 rewire record from the 2026-09-05 session into docs/HARDWARE.md, verbatim:

• the bench sheet (Adafruit hole → UM hole) the breadboard was rewired from (05:54, 06:02),
• the header position-by-position tables with GPIO numbers for both boards,
• the resulting ten board-specific firmware values (Adafruit vs UM), and the three that resolve from the variant without a source change (I²C via Wire.begin(), GPS RX/TX, SPI 36/35/37),
• the caveats carried from that exchange (GPIO 0 in the second 3V position, GPIO 2 not on a header, 33/38 to confirm, an unanswered question about the A2 wire),
• the owner's ruling: wire to match the UM silkscreen so the board can be traced later; keep the Adafruit 5477 assignments so the project can move back.

The Adafruit 5477 tables stay unchanged.

Why

The sheet was drafted on 2026-09-05, offered for docs/HARDWARE.md twice, and never written. On 2026-09-07 a session re-derived the UM pins from the variant header's A0–A5 aliases (the exact mistake retracted at 05:59 two days earlier), produced a wrong "TFT on the wrong pins" table, and stopped a flash the owner had ordered. Three /violation corrections followed. The record exists only in a chat transcript; this issue makes it durable.

Firmware status this records (main @ 1be96cb, 2026-09-07)

platformio.ini has one env, feather_s3 (board = adafruit_feather_esp32s3); every pin define is the Adafruit value. A feather_s3 image on the UM board drives the wrong GPIOs for TFT CS/DC/RST, FRAM_CS, SD_CS, CTP_INT, TFT_BL, the buttons, I²C and the GPS UART. The UM env and board-profile work is separate (under #151); this issue is documentation only.

Acceptance

• docs/HARDWARE.md carries the rewire section with all tables verbatim from the 2026-09-05 record, sourced and dated
• Revision history row added
• No firmware change
• Owner has walked the bench sheet against the physical board (the UM column was read from the FeatherS3D pinout PDF; unverified against hardware as of filing)