Description

Fast wheel-scrolling (esp. near the top of a doc, Ghostty) inserts literal SGR mouse escape residue into the buffer, e.g. '<64;68;26M<64;68;26M...'. Cause: Bubble Tea's input parser splits a burst of SGR mouse sequences across read boundaries and emits the leftover as a KeyRunes text event, which the editor inserts. Mouse is enabled (WithMouseCellMotion) and wheel events ARE handled; this is parser leakage, not missing handling. bubbletea v1.3.10 is already latest. Fix: drop KeyRunes events that are entirely a leaked mouse sequence at the input boundary.

Acceptance Criteria

• #1 A KeyRunes event whose content is entirely SGR mouse residue is ignored, never inserted
• #2 Normal typing (including a lone '<' or text containing '<' / ';') is unaffected

Implementation Notes

Added looksLikeMouseLeak (mouseleak.go): regexp ^(<?\d+;\d+;\d+[Mm])+$ matches a KeyRunes that is entirely SGR mouse residue; guarded at top of app.handleKey to drop it. Defense against Bubble Tea v1.3.10 input parser splitting a burst of wheel-scroll SGR sequences and emitting the tail as text. Normal input (lone '<', text with '<'/';', comparisons) unaffected. TDD, all tests pass.