docs: 文档清理与重构 — 统一为 3 个核心文档

- 删除 5 个过时/残留文档(project_plan/agent_prompt/optimization_plan/report_db_design/deploy/README)
- 新建 docs/architecture.md(项目架构:11 包职责+数据模型+配置+产物)
- 重写 docs/user-guide.md(CLI 全量+增量/断点续跑+MCP+FAQ)
- 重写 README.md(精简入口+文档索引)
- 更新 continuation.md(追加本次记录)
- 更新 .gitignore(排除 data/* 运行产物)

vectorstore/__init__.py

@@ -0,0 +1,25 @@
+"""Qdrant 向量知识库模块 (M6)。
+
+公共 API:
+    - VectorStore:   Qdrant 封装(init / upsert / query / info / count)
+    - SearchFilter / SearchResult / CollectionInfo: 数据模型
+    - make_qdrant_client: 工厂(内存/Docker)
+"""
+
+from .client import (
+    DEFAULT_COLLECTION,
+    DEFAULT_VECTOR_DIM,
+    VectorStore,
+    make_qdrant_client,
+)
+from .models import CollectionInfo, SearchFilter, SearchResult
+
+__all__ = [
+    "DEFAULT_COLLECTION",
+    "DEFAULT_VECTOR_DIM",
+    "CollectionInfo",
+    "SearchFilter",
+    "SearchResult",
+    "VectorStore",
+    "make_qdrant_client",
+]