feat: selezione immagini da cartella IMAGES_DIR via .env

- .env con IMAGES_DIR=Test
- server: _load_env legge .env senza dip extra
- GET /images lista file, POST /load_from_folder carica per nome
- frontend: file picker sostituiti con 2 select popolati all avvio

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pm2d/web/server.py

@@ -9,6 +9,7 @@ Endpoint:
 """
 from __future__ import annotations
 
+import os
 import tempfile
 import time
 import uuid
@@ -21,6 +22,30 @@ from fastapi.responses import HTMLResponse, Response
 from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
 
+
+def _load_env(root: Path) -> None:
+    """Legge .env in root e popola os.environ (no override se già set)."""
+    f = root / ".env"
+    if not f.exists():
+        return
+    for line in f.read_text(encoding="utf-8").splitlines():
+        line = line.strip()
+        if not line or line.startswith("#") or "=" not in line:
+            continue
+        k, v = line.split("=", 1)
+        k = k.strip(); v = v.strip().strip('"').strip("'")
+        os.environ.setdefault(k, v)
+
+
+# Root progetto (parent di pm2d/)
+PROJECT_ROOT = Path(__file__).resolve().parents[2]
+_load_env(PROJECT_ROOT)
+
+_images_dir_raw = os.environ.get("IMAGES_DIR", "Test")
+IMAGES_DIR = Path(_images_dir_raw)
+if not IMAGES_DIR.is_absolute():
+    IMAGES_DIR = PROJECT_ROOT / IMAGES_DIR
+
 from pm2d.line_matcher import LineShapeMatcher, Match
 from pm2d.auto_tune import auto_tune
 
@@ -259,6 +284,39 @@ def index():
     return HTMLResponse(html_path.read_text(encoding="utf-8"))
 
 
+@app.get("/images")
+def list_images():
+    """Lista file immagine nella cartella configurata in IMAGES_DIR."""
+    if not IMAGES_DIR.is_dir():
+        return {"dir": str(IMAGES_DIR), "files": []}
+    exts = {".png", ".jpg", ".jpeg", ".bmp", ".tif", ".tiff"}
+    files = sorted(
+        p.name for p in IMAGES_DIR.iterdir()
+        if p.is_file() and p.suffix.lower() in exts
+    )
+    return {"dir": str(IMAGES_DIR), "files": files}
+
+
+class LoadFolderReq(BaseModel):
+    filename: str
+
+
+@app.post("/load_from_folder", response_model=UploadResp)
+def load_from_folder(req: LoadFolderReq):
+    """Carica immagine dalla cartella IMAGES_DIR per nome file."""
+    name = req.filename
+    if "/" in name or ".." in name:
+        raise HTTPException(400, "nome file non valido")
+    path = IMAGES_DIR / name
+    if not path.is_file():
+        raise HTTPException(404, f"file non trovato: {name}")
+    img = cv2.imread(str(path), cv2.IMREAD_COLOR)
+    if img is None:
+        raise HTTPException(400, "immagine non leggibile")
+    iid = _store_image(img)
+    return UploadResp(id=iid, width=img.shape[1], height=img.shape[0])
+
+
 @app.post("/upload", response_model=UploadResp)
 async def upload(file: UploadFile = File(...)):
     data = await file.read()