docs: prune migration plan to remaining work only
Remove completed feature docs and strip 'What Exists' / 'Status' sections
from all subplans. 17 features verified as done and removed:
SSE auto-reconnect, connection state UI, markdown syntax highlighting,
terminal output visibility, ask mode no edits, SDK over HTTP,
session turn, copy button, chat input resize, chat background color,
clickable cursors, context compression icon, anonymous sign-in prompts,
subagent visibility, diff jump to changed lines, new task discoverability,
reasoning block styling.
Remaining docs contain only TODO items.
kiloconnect[bot]
b98d92c991