feat(web): 项目级配置 + 会话命名/历史 + 设计文档纳入影响调查

- 会话支持 name/project 字段，上传要件定义后自动命名；前端侧边栏会话历史 + localStorage 恢复，顶部只显示会话名
- 新增 ProjectsStore（SQLite）与 /api/projects CRUD；绑定项目后 _rebuild_source 合并模板/规则/代码库/设计文档，上传区仅要件定义
- StructuredSource.design_docs 与 ImpactReport.design_references；影响调查新增既有设计文档确定性交叉引用（无 LLM）
- 同步更新 docs/design.md §12.7、README、_AI_USAGE_LOG.md；全量测试 558 通过，覆盖率 99.10%

src/genesis/server/app.py

@@ -20,7 +20,9 @@ from pydantic import BaseModel
 
 from genesis.inference.factory import build_inference_engine
 from genesis.server.service import FileTypeError, GenesisService, ServiceStepError
-from genesis.server.store import SessionNotFoundError, SessionStore
+from genesis.server.store import (
+    ProjectConfigError, ProjectsStore, SessionNotFoundError, SessionStore,
+)
 
 VERSION = "0.1.0"
 
@@ -47,6 +49,18 @@ class ChatMessageReq(BaseModel):
 
 class SessionCreate(BaseModel):
     user_id: str = "default"
+    name: str | None = None
+    project: str | None = None
+
+
+class ProjectCreate(BaseModel):
+    name: str
+    display_name: str = ""
+    template: str = ""
+    write_instruction: str = ""
+    rules: list[str] = []
+    existing_system_code_dir: str = ""
+    design_docs_dir: str = ""
 
 
 class FileUploadResp(BaseModel):
@@ -75,7 +89,8 @@ def create_app(
     elif engine is None:
         engine = None  # 真实模式：generate/qa 时按需 build（避免未配置 key 直接 503）
 
-    service = GenesisService(store=store, data_root=data_root, engine=engine)
+    projects = ProjectsStore(db_path=str(store._db)) if store else None
+    service = GenesisService(store=store, data_root=data_root, engine=engine, projects=projects)
 
     from genesis.chat.agent import ChatAgent
     chat_agent = ChatAgent(service=service, fake=is_fake, engine=engine)
@@ -95,17 +110,54 @@ def create_app(
     def index():
         return chat_html
 
+    # ---------- 项目配置 ----------
+
+    @app.post("/api/projects")
+    def create_project(body: ProjectCreate):
+        try:
+            cfg = service.projects.upsert(
+                name=body.name, display_name=body.display_name, template=body.template,
+                write_instruction=body.write_instruction, rules=body.rules,
+                existing_system_code_dir=body.existing_system_code_dir,
+                design_docs_dir=body.design_docs_dir,
+            )
+        except ProjectConfigError as e:
+            raise _error(400, "PROJECT_CONFIG_INVALID", str(e))
+        return cfg.to_dict
+
+    @app.get("/api/projects")
+    def list_projects():
+        if not service.projects:
+            return []
+        return [c.to_dict for c in service.projects.list()]
+
+    @app.get("/api/projects/{name}")
+    def get_project(name: str):
+        if not service.projects:
+            raise _error(404, "PROJECT_NOT_FOUND", f"项目不存在: {name}")
+        cfg = service.projects.get(name)
+        if cfg is None:
+            raise _error(404, "PROJECT_NOT_FOUND", f"项目不存在: {name}")
+        return cfg.to_dict
+
+    @app.delete("/api/projects/{name}")
+    def delete_project(name: str):
+        if not service.projects:
+            return {"deleted": False}
+        return {"deleted": service.projects.delete(name)}
+
     # ---------- 会话 ----------
 
     @app.post("/api/sessions")
     def create_session(body: SessionCreate):
-        rec = service.create_session(body.user_id)
-        return {"session_id": rec.session_id, "status": rec.status}
+        rec = service.create_session(body.user_id, name=body.name, project=body.project)
+        return {"session_id": rec.session_id, "status": rec.status, "name": rec.name}
 
     @app.get("/api/sessions")
     def list_sessions(user_id: str = "default"):
         return [
-            {"session_id": r.session_id, "status": r.status, "updated_at": r.updated_at}
+            {"session_id": r.session_id, "name": r.name, "project": r.project,
+             "status": r.status, "updated_at": r.updated_at}
             for r in service.store.list_sessions(user_id)
         ]