feat: dashboard web FastAPI Sprint 4

Ajout d'un dashboard lecture seule par-dessus la DB SQLite existante.

Fichiers créés :
  - tickettracker/web/queries.py   : 7 fonctions SQL (stats, compare, historique...)
  - tickettracker/web/api.py       : router /api/* JSON (FastAPI)
  - tickettracker/web/app.py       : routes HTML + Jinja2 + point d'entrée uvicorn
  - tickettracker/web/templates/   : base.html, index.html, compare.html, product.html, receipt.html
  - tickettracker/web/static/style.css : personnalisations Pico CSS
  - tests/test_web.py              : 19 tests (96 passent, 1 xfail OCR)

Fichiers modifiés :
  - requirements.txt : +fastapi, uvicorn[standard], jinja2, python-multipart, httpx
  - config.py        : +DB_PATH (lu depuis TICKETTRACKER_DB_PATH)

Lancement : python -m tickettracker.web.app

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tickettracker/web/app.py

@@ -0,0 +1,206 @@
+"""
+Application web FastAPI pour le dashboard TicketTracker.
+
+Routes HTML (lecture seule) :
+  GET /                    → index.html  (stats + graphique + derniers tickets)
+  GET /compare             → compare.html (comparaison Picnic vs Leclerc)
+  GET /product/{name:path} → product.html (historique d'un produit)
+  GET /receipt/{id}        → receipt.html (détail d'un ticket)
+
+Lancement :
+  python -m tickettracker.web.app
+  ou
+  TICKETTRACKER_DB_PATH=/autre/chemin.db python -m tickettracker.web.app
+"""
+
+import json
+from pathlib import Path
+from urllib.parse import quote
+
+from fastapi import FastAPI, Request
+from fastapi.responses import HTMLResponse
+from fastapi.staticfiles import StaticFiles
+from fastapi.templating import Jinja2Templates
+
+import tickettracker.config as config
+from tickettracker.db.schema import get_connection, init_db
+from tickettracker.web.api import router as api_router
+from tickettracker.web.queries import (
+    get_all_receipts,
+    get_compare_prices,
+    get_dashboard_stats,
+    get_monthly_spending,
+    get_product_history,
+    get_product_list,
+    get_receipt_detail,
+)
+
+# ---------------------------------------------------------------------------
+# Initialisation de l'application
+# ---------------------------------------------------------------------------
+
+app = FastAPI(title="TicketTracker Dashboard", docs_url="/api/docs", redoc_url=None)
+
+# Répertoires statiques et templates (relatifs à ce fichier)
+_WEB_DIR = Path(__file__).parent
+_STATIC_DIR = _WEB_DIR / "static"
+_TEMPLATES_DIR = _WEB_DIR / "templates"
+
+app.mount("/static", StaticFiles(directory=str(_STATIC_DIR)), name="static")
+
+templates = Jinja2Templates(directory=str(_TEMPLATES_DIR))
+
+# Filtre Jinja2 pour encoder les noms de produits dans les URLs
+templates.env.filters["urlquote"] = lambda s: quote(str(s), safe="")
+
+# Router API JSON
+app.include_router(api_router)
+
+
+# ---------------------------------------------------------------------------
+# Helper : transforme la liste plate monthly en structure Chart.js
+# ---------------------------------------------------------------------------
+
+def _build_monthly_chart_data(monthly: list[dict]) -> dict:
+    """Convertit [{month, store, total}] en structure datasets Chart.js stacked bar.
+
+    Retourne un dict sérialisable en JSON :
+    {
+        "labels": ["2026-01", ...],
+        "datasets": [
+            {"label": "picnic",  "data": [...], "backgroundColor": "#4a9eff"},
+            {"label": "leclerc", "data": [...], "backgroundColor": "#ff6b35"},
+        ]
+    }
+    Les totaux manquants (enseigne absente pour un mois) sont mis à 0.
+    """
+    # Extraire tous les mois et enseignes distincts (ordonnés)
+    labels = sorted({row["month"] for row in monthly})
+    stores = sorted({row["store"] for row in monthly})
+
+    # Construire un index {(month, store): total} pour lookup rapide
+    index = {(row["month"], row["store"]): row["total"] for row in monthly}
+
+    # Couleurs associées aux enseignes
+    colors = {"picnic": "#4a9eff", "leclerc": "#ff6b35"}
+
+    datasets = [
+        {
+            "label": store,
+            "data": [index.get((month, store), 0) for month in labels],
+            "backgroundColor": colors.get(store, "#888888"),
+        }
+        for store in stores
+    ]
+
+    return {"labels": labels, "datasets": datasets}
+
+
+# ---------------------------------------------------------------------------
+# Routes HTML
+# ---------------------------------------------------------------------------
+
+@app.get("/", response_class=HTMLResponse)
+async def page_index(request: Request):
+    """Page d'accueil : statistiques globales + graphique + liste des tickets."""
+    conn = get_connection(config.DB_PATH)
+    try:
+        stats = get_dashboard_stats(conn)
+        monthly = get_monthly_spending(conn)
+        receipts = get_all_receipts(conn)
+    finally:
+        conn.close()
+
+    chart_data = _build_monthly_chart_data(monthly)
+    empty = stats["total_receipts"] == 0
+
+    return templates.TemplateResponse(
+        request,
+        "index.html",
+        {
+            "stats": stats,
+            "chart_data": chart_data,
+            "receipts": receipts,
+            "empty": empty,
+        },
+    )
+
+
+@app.get("/compare", response_class=HTMLResponse)
+async def page_compare(request: Request):
+    """Page de comparaison des prix Picnic vs Leclerc."""
+    conn = get_connection(config.DB_PATH)
+    try:
+        products = get_compare_prices(conn)
+    finally:
+        conn.close()
+
+    return templates.TemplateResponse(
+        request,
+        "compare.html",
+        {
+            "products": products,
+            "empty": len(products) == 0,
+        },
+    )
+
+
+@app.get("/product/{name:path}", response_class=HTMLResponse)
+async def page_product(request: Request, name: str):
+    """Page historique d'un produit normalisé."""
+    conn = get_connection(config.DB_PATH)
+    try:
+        data = get_product_history(conn, name)
+        all_products = get_product_list(conn)
+    finally:
+        conn.close()
+
+    return templates.TemplateResponse(
+        request,
+        "product.html",
+        {
+            "data": data,
+            "name": name,
+            "all_products": all_products,
+            "empty": data is None,
+        },
+    )
+
+
+@app.get("/receipt/{receipt_id}", response_class=HTMLResponse)
+async def page_receipt(request: Request, receipt_id: int):
+    """Page détail d'un ticket."""
+    conn = get_connection(config.DB_PATH)
+    try:
+        data = get_receipt_detail(conn, receipt_id)
+    finally:
+        conn.close()
+
+    if data is None:
+        return templates.TemplateResponse(
+            request,
+            "receipt.html",
+            {"data": None, "receipt_id": receipt_id},
+            status_code=404,
+        )
+
+    return templates.TemplateResponse(
+        request,
+        "receipt.html",
+        {"data": data},
+    )
+
+
+# ---------------------------------------------------------------------------
+# Point d'entrée : python -m tickettracker.web.app
+# ---------------------------------------------------------------------------
+
+if __name__ == "__main__":
+    import uvicorn
+
+    # S'assurer que la DB existe (idempotent)
+    init_db(config.DB_PATH)
+
+    print(f"Base de données : {config.DB_PATH}")
+    print("Dashboard disponible sur http://localhost:8000")
+    uvicorn.run("tickettracker.web.app:app", host="0.0.0.0", port=8000, reload=True)