feat(projets): racine active par contextvar + projet par session

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/routes/sessions.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 from fastapi import APIRouter, HTTPException
 from pydantic import BaseModel
 
-from .. import db
+from .. import db, tools
 
 router = APIRouter(prefix="/api/sessions", tags=["sessions"])
 
@@ -12,10 +12,12 @@ router = APIRouter(prefix="/api/sessions", tags=["sessions"])
 class CreateSession(BaseModel):
     title: str = "Nouvelle session"
     model: str | None = None
+    project: str | None = None
 
 
-class RenameSession(BaseModel):
-    title: str
+class UpdateSession(BaseModel):
+    title: str | None = None
+    project: str | None = None  # "" = retour à la racine du workspace
 
 
 @router.get("")
@@ -25,7 +27,9 @@ async def get_sessions() -> dict:
 
 @router.post("")
 async def post_session(req: CreateSession) -> dict:
-    return db.create_session(req.title, req.model)
+    if req.project and not tools.PROJECT_NAME.match(req.project):
+        raise HTTPException(400, "nom de projet invalide")
+    return db.create_session(req.title, req.model, req.project or None)
 
 
 @router.get("/{sid}")
@@ -37,10 +41,16 @@ async def get_one(sid: str) -> dict:
 
 
 @router.patch("/{sid}")
-async def patch_session(sid: str, req: RenameSession) -> dict:
+async def patch_session(sid: str, req: UpdateSession) -> dict:
     if not db.get_session(sid):
         raise HTTPException(404, "session introuvable")
-    db.rename_session(sid, req.title)
+    if req.title is not None:
+        db.rename_session(sid, req.title)
+    if req.project is not None:
+        project = req.project or None
+        if project and not tools.PROJECT_NAME.match(project):
+            raise HTTPException(400, "nom de projet invalide")
+        db.set_session_project(sid, project)
     return {"ok": True}