feat(swarm): real bias-fix prompt (gate 13) on GLM-5.2
- Add bias_fixed_prompt (gate 13 calibration): sector-median company = neutral,
mediocre-but-stable = neutral not bearish, symmetric bull/bear, null = average.
- Wire B screen tier, C, control-BC to bias_fixed; A stays on original screen_prompt
(correctly fails gate 13 on merit = the CEO's 65%-bearish complaint).
- Fix bias_control NUMERIC_FIELDS to real eligible field names (revenue_ttm, net_income)
so sector medians actually compute.
- Live evidence (captured, GLM-5.2 over SSH tunnel, 500-co control each):
control-A (original): 57 bull / 270 bear / 125 neutral -> diff=0.651 (FAIL, bearish)
control-BC (fixed): 14 bull / 68 bear / 402 neutral -> diff=0.659 (FAIL, residual)
The bias fix cuts bearish share by pushing average -> neutral, but GLM-5.2 still
emits ~5:1 bear:bull on the directional calls it commits to. Prompt calibration
cannot fully remove this model-level pessimistic bias -> gate 13 honest blocker.
- bias_control tests updated to new field names (64 pass).