- Move import modal visibility into ImportContext so the Layout
progress pill can reopen the result dialog after the modal was closed.
- Raise LLM progress cap from 85% to 98% and drop the intermediate
-import 88%- SSE event to eliminate the visual stall after LLM finishes.
- Detect LLM context-length errors (n_keep >= n_ctx) and surface a
clear message instead of generic -Временная ошибка конвертации-.
Replace the synchronous PDF import with Server-Sent Events streaming
between the backend (LLM) and the browser. The user can now close the
import modal and continue working while the conversion runs — a fixed
progress bar in the Layout shows real-time stage and percentage.
