[danielbrownjr]

Summary

Adds heater-incapable TinyS3D candidate bring-up scaffolding on top of the existing candidate characterization work.

Included

• product-local jj_board candidate identity
• read-only jj_bringup diagnostics
• boot/runtime chip, flash, reset, heap and PSRAM observations
• Wi-Fi association/IP/DHCP observations
• host-testable configuration callbacks
• explicit unknown/unavailable diagnostic states
• TinyS3D reverse-voltage observation documentation

Safety boundaries

• firmware remains heater-incapable
• no actuator GPIO/PWM path
• no production heater/fan/ADC implementation
• no control-authority change
• no safety-policy change
• no PrusaLink-policy change
• no provisional GPIO assignment promoted to verified
• PSRAM presence is not assumed
• 5 V/VBUS isolation/backfeed remains unresolved

Validation

Published head:
406ea45

CI passed on the exact pushed head.

Validated:

• existing interlock host tests
• bring-up serialization and board fixtures
• configuration and secret-retention fixtures
• PSRAM/Wi-Fi adapter fixtures
• identity/API/OTA/actuation checks
• cppcheck
• warnings-as-errors
• host UBSan
• git diff --check
• ESP32-S3 target build

No physical HIL testing was performed.

Physical work still required

• loaded 5 V/VBUS retest
• PSRAM verification on the real module
• real-network Wi-Fi provisioning
• antenna behavior
• caliper measurements
• GPIO/mounting validation

TinyS3D remains a prototype candidate, not a production-final selection.