feat(ssa): Complete Phase 2A frontend integration - multi-step workflow end-to-end

Phase 2A: WorkflowPlannerService, WorkflowExecutorService, Python data quality, 6 bug fixes, DescriptiveResultView, multi-step R code/Word export, MVP UI reuse. V11 UI: Gemini-style, multi-task, single-page scroll, Word export. Architecture: Block-based rendering consensus (4 block types). New R tools: chi_square, correlation, descriptive, logistic_binary, mann_whitney, t_test_paired. Docs: dev summary, block-based plan, status updates, task list v2.0.

Co-authored-by: Cursor <cursoragent@cursor.com>

r-statistics-service/docker-compose.yml

@@ -11,6 +11,7 @@ services:
       - DEV_MODE=true
     volumes:
       # 开发环境挂载：支持热重载
+      - ./plumber.R:/app/plumber.R
       - ./tools:/app/tools
       - ./utils:/app/utils
       - ./tests:/app/tests