init: F3 unlock project — ESP32-C3 bridge + procedure for CLAR200 Exos X18

CLAUDE.md

@@ -0,0 +1,39 @@
+# clar200-unlock
+
+> Unlock EMC CLAR200-locked Exos X18 SAS drives via the Seagate F3 terminal, using an ESP32-C3 bridge.
+
+## Start Here
+
+**Read the latest handoff first:** `.claude/handoffs/` (most recent file).
+Then `PROCEDURE.md` (the runbook), `IDEA.md` (brief), `DECISIONS.md` (settled choices).
+Background on why host-side tools fail: `~/bin/EMC_CLAR200_DRIVE_FIX_NOTES.md`.
+
+## Project Identity
+
+Two Seagate Exos X18 SAS drives (ST16000NM004J, EMC fw ES2264 — SN ZRS015V7,
+ZR511KWK) are locked in the "SS160520 CLAR200" state: SCSI INQUIRY/VPD work, but
+every other command (incl. READ CAPACITY) returns Hardware Error. No host tool
+can format them. This project drives the drives' out-of-band **F3 service UART**
+(via an ESP32-C3 as a 3.3 V USB-serial bridge) to reformat them to 512-byte
+sectors and reclaim them as 14.6 TB+ spares for the `tank` pool.
+
+## Current State
+
+- **Phase:** building → first hardware attempt pending
+- **Repo:** https://git.sethpc.xyz/Seth/clar200-unlock
+- **Hardware:** ESP32-C3 on steel141 `/dev/ttyACM0` (MAC 58:8c:81:ac:f0:4c).
+  Drive ZRS015V7 in a pve173 JBOD (must be benched for F3 work).
+- **Done:** firmware (`firmware/clar200_bridge.ino`) + flash script + full
+  procedure written.
+- **Next:** `./firmware/flash.sh`, sanity-test bridge, bench drive, find F3
+  pinout, get `F3 T>`, format to 512.
+
+## Conventions
+
+- **Safety:** bench-only F3 work — NEVER in the pve173 JBOD next to live tank.
+  3.3 V only; share TX/RX/GND, never power. `screen -L` to log every session.
+  Escalation brake applies: silent terminal → re-check wiring/baud, never a more
+  aggressive format command.
+- **F3 honesty:** Exos X18 dialect ≠ 7200.11. Map commands with `?` before
+  firing; record discovered tokens in `docs/f3-command-reference.md`.
+- Conventional commits; commit + `gitea push` each meaningful change.