Brings in the external FEM gain preferences (fem_txgain, PR #3137 plus the
companion-side port), the AGC reset rxgain fix, the LR2021 preamble/IRQ
timeout logic, and assorted variant fixes (T096, T-Echo Card TCXO, promicro
pinmap, minewsemi, R1 Neo).
Conflict resolutions:
- SH1106Display: both sides fixed T-Beam Supreme startup independently. Kept
our _initialized guard and DISPLAY_ADDRESS_ALT override, took upstream's
SA0-pair fallback and its unconditional display.begin() so the frame buffer
is allocated even when no panel answers.
- MyMesh/SensorMesh/CommonCLI: took upstream's fem_txgain default and wiring,
kept our comments and the observer-side prefs layout.
Also fixes CustomLLCC68Wrapper, which upstream missed when sx126xResetAGC
gained its rx_boost_gain parameter. No variant builds that wrapper today, so
neither tree failed to compile.
agessaman
ced0eb3780