feat: add --debounce option to wait, update docs

[onesuper]

Problem

wait resolved after a fixed 100ms idle window with no way to tune it. Programs with unpredictable timing — pdb stepping through slow code, large computations, TUI apps with complex redraws — required agents to add sleep calls as a
workaround, which is exactly what tui-use is supposed to eliminate.

Solution

Added a --debounce option to wait. The debounce window controls how long the screen must be stable before wait resolves. It resets on every change, so a program that keeps outputting keeps wait blocked until the output truly
settles.

• timeout (existing) — the hard deadline; wait returns regardless when this expires
• --debounce (new, default 100ms) — the stability window; increase for slow programs

tui-use wait --debounce 300 # wait until 300ms of silence (slow programs)
tui-use wait 5000 --debounce 500 # 5s deadline, 500ms stability window

Changes

• session.wait() accepts optional debounceMs parameter (default 100)
• WaitRequest protocol type adds debounce_ms?: number
• CLI wait command adds --debounce option
• README: rewrote How It Works to focus on the wait model; clarified Why not tmux
• SKILL.md: simplified structure, fixed Core Workflow, added --text semantic signal guidance
• Plugin version bumped to 0.4.0

Tests

• uses 100ms debounce by default
• respects custom debounceMs
• custom debounceMs resolves after specified idle time