fix(orderbook): clarify insufficient replacement quantity

[jackhai9]

When same-direction cancellable orders total less than the ladder replacement target, the script currently reports that no replacement orders were selected. Clarify the Chinese and English messages to explain the quantity shortfall and that existing orders were not cancelled. Preserve the existing selection threshold, return status, and cancellation flow.

Bump the orderbook userscript to 2.7.208 and regenerate its install artifact.

Validation:

• Full npm test: 1,032 passed on Node 24.16.0.
• Orderbook build, syntax check, and git diff --check passed.
• Independent read-only review verified a copy-only diff and exact in-memory build equality.
• Isolated Chromium reproduction displayed the final message and complete title, preserved the existing order, emitted zero cancel/submit events, restored the symbol filter, and returned the start button to ready.