revert(loader): multi-resolution default '1:32' (single-scale) after htpp6 falsification

The Phase 1 multi-resolution layout (10 raw + 10 agg@30 + 12 agg@100)
regressed ALL horizons in alpha-perception-htpp6 (2026-05-22):
- auc_h100:  0.681 -> 0.512  (-0.169)
- auc_h300:  0.617 -> 0.506  (-0.111)
- auc_h1000: 0.576 -> 0.526  (-0.050)

Hypothesis falsified. Root cause: Mamba2+CfC SSM encoder already used
all 32 raw ticks effectively via state-recurrence; replacing 22 raw
ticks with arithmetic-mean aggregates destroyed within-window
microstructure variance (the actual h100 signal) AND broke temporal
continuity that the recurrence relies on. Δt Fourier encoder
couldn't compensate.

Architectural pearl: SSM/RNN/CfC + multi-resolution input is
incompatible without separate-encoder-per-scale or explicit scale
tokens. Transformer-style positional encoding tolerates scale-mixing;
recurrent state updates assume consecutive positions.

Reverts default to '1:32'. Adds explicit single_scale_32() constructor
for callers (harness, tests). Keeps default_three_scale() in code with
deprecation note for future sub-variant experiments. Production
defaults across alpha_train CLI, Argo template, dispatcher script,
ml-backtesting harness now match the proven baseline.

scripts/argo-alpha-perception.sh

@@ -20,7 +20,7 @@ SHA=HEAD
 BRANCH=$(git symbolic-ref --short HEAD 2>/dev/null || echo "ml-alpha-phase-a")
 GPU_POOL=ci-training-l40s
 EPOCHS=5
-MULTI_RESOLUTION="1:10,30:10,100:12"
+MULTI_RESOLUTION="1:32"
 MAMBA2_STATE_DIM=16
 LR_CFC=3e-3
 LR_MAMBA2=1e-3