Extends the Move Log panel's single active-row to a 3-row recent-
history window: 2 prev rows showing the moves applied just before
the active one, then the active row. Display order top-to-bottom:
header → prev offset 2 (oldest) → prev offset 1 → active.
Panel grows from 56 → 84 px to fit the additional rows. Active
row keeps TEXT_PRIMARY; prev rows render in TEXT_SECONDARY so
the active row stands out from context rows even without an
explicit highlight. (Active-row highlight is a follow-up commit.)
The format helper generalises:
- New `format_kth_recent_row(state, k)` returns the text for the
kth-most-recently-applied move (k=1 is active, k=2 is row above,
etc.). Returns empty when k > cursor (early-replay under-fill)
or k = 0 (degenerate).
- `format_active_move_row` becomes a thin wrapper for k=1, kept
at module scope so call sites stay readable.
New `ReplayOverlayMoveLogPrevRow { offset: u8 }` component carries
the row's offset (1 = just-before-active, 2 = before that). Spawn
loop iterates `MOVE_LOG_PREV_ROWS..=1` in reverse so the highest-
offset (oldest) row sits topmost in the panel's flex column.
Per-frame `update_move_log_prev_rows` system reads each row's
offset, computes k = offset + 1, and repaints via
format_kth_recent_row. Empty-when-out-of-range means panels gracefully
under-fill at cursor=1 (only active populated) and cursor=2
(active + offset 1, offset 2 empty).
4 new tests:
- format_kth_recent_row: k=1, 2, 3 in-range cases + k>cursor
out-of-range + k=0 degenerate.
- move_log_prev_rows_spawn_with_panel: cardinality matches the
MOVE_LOG_PREV_ROWS const.
- move_log_prev_rows_paint_helper_strings_at_spawn: text matches
helper output per offset.
- move_log_prev_rows_repaint_on_cursor_advance: drives cursor=2
→ cursor=5 and asserts offset 1 / offset 2 texts follow.
Tests: 1262 → 1266. Clippy clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
funman300
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