92591e5dc0
Rename the dense PositionManagement record's column 9 from `bias_at_entry_abs` to `conviction_at_entry` (FIELD_NAMES, the `r_col`/test index constants, the cross-crate layout guard, and the doc comments). Why: the column holds |bias| at entry, which C10 defines AS conviction (bias = direction + conviction magnitude; ledger INDEX.md ~458). The record already names the other half of that decomposition by its domain concept (`direction` = sign, not `bias_sign`), so naming the magnitude half mechanically (`bias_at_entry_abs`) was an inconsistency; `conviction_at_entry` speaks the ledger's ubiquitous language and parallels `direction`, while `_at_entry` preserves the frozen-snapshot precision. Considered and rejected: collapsing `(direction, bias_at_entry_abs)` into one signed `bias_at_entry` and dropping `direction` as redundant — it is not redundant. On a reversal row col 4 (`direction`) tracks the reopened leg while col 9 tracks the closed trade's entry conviction, so the two describe different trades and cannot be losslessly merged; they are also distinct semantic axes (current-position direction vs per-trade entry conviction). Scope: domain name at the data boundary, mechanical name internally — the internal `bias.abs()` variables (`Open.bias_abs`, the fold's `Trade.bias_abs`) keep their computation-faithful names, exactly the raw-internal / domain-external split the record uses elsewhere. Behaviour-preserving: cargo build --workspace clean; cargo test --workspace 500 passed, 0 failed (unchanged); clippy --all-targets -D warnings clean. The layout guard (`r_col_indices_match_producer_field_layout`) confirms the renamed string. refs #117