Bottom-panel Stage 2A, second half (Q#BP8, Q#BP17). Still no protocol
change and no behavior change: `paint_frame` builds the same fold map
it always did and passes it in, so grid rendering is unchanged.
Two extractions, both taking the fold map as a **parameter** rather
than building it:
- `prepare_window_cursor_visible` — the active-window auto-scroll
clamp. The panel band (2B) runs this for its own window when that
window owns focus, and leaves a passive panel's `view_top` alone.
- `paint_window_content` — the per-window document body: text, gutter,
overlays, selection, and the mode line. The panel paints into a
panel-sized grid at the same origin-agnostic `Viewport`, so this is
that body lifted out, not a second painter (Bet B2').
The parameter is the point (Q#BP17). Folding built its per-window map
ungated on the premise that "a semantic session never enters
`paint_frame`", which the panel band breaks. The panel path must pass
`None` for a frontend whose `fold_projection` is false, and must not
call `EditorCore::fold_map_for_window` — that gates on the **active**
frontend, which is right for command-time reckoning and wrong for
painting another frontend's panel.
`tests/bottom_panel_stage2a_acceptance.rs` — 10 tests. The negative
half is the load-bearing half, so Projection assertions are paired
with focus-class assertions taken in the SAME state:
- `focus_and_projection_disagree_in_the_same_state` is the key one:
with a panel focused, the focus authority must name the panel while
the projection authority names the document. Routing the focus class
through `primary_document_window` fails this even though every
Projection test still passes.
- The statusline pair pins the split: the LOOKUP resolves the document
window while `active` reports actual focus, with a non-vacuity twin
that flips `active` back to true when focus returns.
- The extraction pair pins cells, the returned cursor, the focused
window's `view_top`, AND a passive window's untouched scroll —
identical cells alone would not catch a clamp that moved to the
wrong window on a single-window frame.
- `the_panel_fixture_really_builds_a_side_window` pins the fixture's
own precondition, since every other test is worthless if
`focused_panel` silently produced an ordinary split.
One crdt-gated caller of the old `align_semantic_window_to_buffer` was
updated; it compiles only under `--features crdt`, which is the
config CI never runs.
1,832 default + 2,009 CRDT library tests, 10 new acceptance; fmt and
workspace clippy clean.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>