feat(maker): AI parsing schede tecniche PDF via OpenRouter

- Nuovo servizio ai_service.py: estrae testo da PDF (pdfplumber) + analisi AI (OpenRouter)
- Endpoint POST /api/recipes/{id}/parse-technical-sheet con validazione file
- UI: bottone "Importa da PDF" nel task editor con modale upload + preview editabile
- Task suggeriti modificabili/rimovibili prima della creazione bulk
- Config: OPENROUTER_API_KEY e OPENROUTER_MODEL in .env
- Dipendenze: pdfplumber + httpx aggiunti a server deps

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

src/backend/api/routers/recipes.py

@@ -1,5 +1,7 @@
-"""Recipe router - CRUD, versioning, barcode lookup."""
-from fastapi import APIRouter, Depends, Query
+"""Recipe router - CRUD, versioning, barcode lookup, AI parsing."""
+import logging
+
+from fastapi import APIRouter, Depends, File, HTTPException, Query, UploadFile, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from src.backend.database import get_db
@@ -164,3 +166,31 @@ async def get_measurement_count(
     """
     count = await recipe_service.get_measurement_count(db, recipe_id, version_number)
     return {"recipe_id": recipe_id, "version_number": version_number, "measurement_count": count}
+
+
+@router.post("/{recipe_id}/parse-technical-sheet")
+async def parse_technical_sheet(
+    recipe_id: int,
+    file: UploadFile = File(...),
+    _user: User = Depends(require_maker),
+    db: AsyncSession = Depends(get_db),
+):
+    """Parse a PDF technical sheet using AI and return suggested tasks."""
+    from src.backend.services import ai_service
+
+    if not file.content_type or "pdf" not in file.content_type:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Il file deve essere un PDF")
+
+    pdf_bytes = await file.read()
+    if len(pdf_bytes) > 20 * 1024 * 1024:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="File troppo grande (max 20MB)")
+
+    try:
+        tasks = await ai_service.parse_technical_sheet(pdf_bytes)
+    except ValueError as e:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(e))
+    except Exception as e:
+        logging.getLogger(__name__).error("AI parsing error: %s", e)
+        raise HTTPException(status_code=status.HTTP_502_BAD_GATEWAY, detail="Errore nel servizio AI")
+
+    return {"recipe_id": recipe_id, "suggested_tasks": tasks}

src/backend/config.py

@@ -34,6 +34,10 @@ class Settings(BaseSettings):
     # Setup page (empty = disabled)
     setup_password: str | None = None
 
+    # AI / OpenRouter (for technical sheet parsing)
+    openrouter_api_key: str | None = None
+    openrouter_model: str = "anthropic/claude-sonnet-4"
+
     @property
     def database_url(self) -> str:
         """Async MySQL connection string."""

src/backend/services/ai_service.py

@@ -0,0 +1,74 @@
+"""AI service for parsing technical sheets via OpenRouter."""
+import json
+import logging
+from io import BytesIO
+
+import httpx
+import pdfplumber
+
+from src.backend.config import settings
+
+logger = logging.getLogger(__name__)
+
+SYSTEM_PROMPT = """Sei un assistente specializzato nell'analisi di schede tecniche industriali.
+Analizza il testo estratto da una scheda tecnica e identifica i blocchi operativi distinti.
+Per ogni blocco, estrai:
+- title: titolo breve del blocco (es. "MATERIALI", "TEMPERATURA", "MISURA", "IMBALLO")
+- directive: istruzione operativa principale (es. "VERIFICARE ATTREZZATURE")
+- description: dettagli completi del blocco, preservando gli "a capo" originali
+
+Rispondi SOLO con un array JSON valido, senza markdown o testo aggiuntivo.
+Esempio:
+[
+  {"title": "MATERIALI", "directive": "Verificare materiali", "description": "RIGIDO (36): AFT9/UV CRI 7\\nMORBIDO (E38): M70"},
+  {"title": "TEMPERATURA", "directive": "Verificare impostazioni", "description": "RIGIDO: TEMP: 170/170/170/170/170\\nMORBIDO: TEMP: 130-135-140-145"}
+]"""
+
+
+def extract_text_from_pdf(pdf_bytes: bytes) -> str:
+    with pdfplumber.open(BytesIO(pdf_bytes)) as pdf:
+        pages = []
+        for page in pdf.pages:
+            text = page.extract_text()
+            if text:
+                pages.append(text)
+        return "\n\n---\n\n".join(pages)
+
+
+async def parse_technical_sheet(pdf_bytes: bytes) -> list[dict]:
+    text = extract_text_from_pdf(pdf_bytes)
+    if not text.strip():
+        return []
+
+    if not settings.openrouter_api_key:
+        raise ValueError("OPENROUTER_API_KEY non configurata")
+
+    async with httpx.AsyncClient(timeout=60) as client:
+        resp = await client.post(
+            "https://openrouter.ai/api/v1/chat/completions",
+            headers={
+                "Authorization": f"Bearer {settings.openrouter_api_key}",
+                "Content-Type": "application/json",
+            },
+            json={
+                "model": settings.openrouter_model,
+                "messages": [
+                    {"role": "system", "content": SYSTEM_PROMPT},
+                    {"role": "user", "content": f"Analizza questa scheda tecnica ed estrai i task:\n\n{text}"},
+                ],
+                "temperature": 0.1,
+            },
+        )
+        resp.raise_for_status()
+
+    data = resp.json()
+    content = data["choices"][0]["message"]["content"].strip()
+
+    # Strip markdown fences if present
+    if content.startswith("```"):
+        content = content.split("\n", 1)[1]
+        if content.endswith("```"):
+            content = content[:-3]
+        content = content.strip()
+
+    return json.loads(content)