animation: core publishes transition records; gui evaluates via shaders, tty over grid cells

1 files changed, 20 insertions, 5 deletions

diff --git a/docs/config.md b/docs/config.md
index 7e27216b..6485d46a 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -100,6 +100,13 @@ neighbour instead of leaving the body grid stable. `Config` reports the active
 percentage. The browser applies the same compiled percentage to its DOM glyphs
 but has no runtime setter.
 
+The SDL GUI joins the reduced-height global and pane tagline bands with
+`gui_topbar_pane_border_px` physical pixels. Set it to zero for a direct join.
+`gui_topbar_pane_border_rgb` can pin an RGB color; its default `null` follows
+the active theme's scrollbar-track color. With `Tagbottom` enabled, a tagline
+on the final grid row is bottom-aligned so the same unused half-band does not
+show beneath it.
+
 What happens to a codepoint the chosen face has no glyph for differs by shell.
 The SDL GUI falls back through a chain it builds itself: embedded Adwaita
 Mono, then installed `NotoSansMono-Regular`, `DejaVuSansMono`,
@@ -132,12 +139,20 @@ PanelVertical
 
 All panel transitions start off. Slide uses cubic ease-out and zoom uses an
 overshooting ease-out-back. Dissolve and ASCII compare the last successfully
-presented grid with the new one: cells which did not change are immediately
-canonical, while changed cells cross from old to new through smoothstep or
-stable themed punctuation. Vertical is a pane-lifecycle effect: a newly added
+presented grid with the new one. Dissolve switches visually changed cells at
+stable noise thresholds. ASCII walks every changed single-byte printable glyph
+from its old `u8` value to its new one. Nearby values increment or decrement
+once per frame; longer distances use ease-out character skips, moving quickly
+at first and settling exactly on the destination. Glyph-stable style changes
+and non-ASCII graphemes become canonical immediately. A walk is capped at
+twelve movement frames, and each pane lasts only as long as its longest walk.
+The core computes and composes that semantic diff once for every backend;
+pixel attachments, which have no character value, pass through unchanged.
+Vertical is a pane-lifecycle effect: a newly added
 pane rises from below inside its own fixed box, and a deleted pane's frozen
-content rises out; surviving panes are never animated. The TTY implementation
-performs those operations directly on a copy of the canonical cell grid.
+content drops back down; surviving panes are never animated. The TTY
+implementation performs its remaining geometry/dissolve operations directly
+on a copy of the core-composed presentation grid.
 The SDL and native macOS GUI implementations pass plain panel tracks to their
 GPU shaders, including native image/PDF pixels; layout itself commits
 immediately and remains the one authoritative geometry. DOM web intentionally