feat: Phase 5 – PDF/Bild-Beleg-Import (lokal, Tesseract-OCR)

Backend:
- services/ocr: PDF-Text via PyMuPDF, OCR (Tesseract) für Scans/Bilder,
  heuristischer Parser (Datum + Betrag je Zeile, CH/DE/US-Beträge).
- routers/documents: /documents/preview (Upload -> Text -> Kandidaten ->
  gemeinsame Prüf-/Buchungslogik des CSV-Imports). csv_import refaktoriert:
  detect_rows() von CSV und Beleg gemeinsam genutzt.
- requirements: PyMuPDF, pytesseract, pillow; install.sh installiert tesseract-ocr
  (+ deu). pytest: Heuristik-Parser und PDF-Vorschau.

Frontend:
- Import-Seite: CSV/PDF-Umschalter; PDF-Modus mit Beleg-Auslesen, extrahiertem
  Text zur Kontrolle und Best-Effort-Hinweis; gleiche Prüfansicht + Buchen.

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

web/src/pages/Import.jsx

@@ -41,11 +41,13 @@ export default function Import() {
   const [presets, setPresets] = useState([]);
   const [batches, setBatches] = useState([]);
 
+  const [mode, setMode] = useState("csv"); // "csv" | "doc"
   const [accountId, setAccountId] = useState("");
   const [file, setFile] = useState(null);
   const [config, setConfig] = useState(defaultConfig());
   const [raw, setRaw] = useState(null);
   const [rows, setRows] = useState(null);
+  const [docText, setDocText] = useState("");
   const [busy, setBusy] = useState(false);
   const [saveName, setSaveName] = useState("");
 
@@ -117,6 +119,19 @@ export default function Import() {
     } catch (e) { toast(e.message, "error"); } finally { setBusy(false); }
   }
 
+  async function loadDoc() {
+    if (!file || !accountId) { toast(t("import.needFileAccount"), "error"); return; }
+    setBusy(true);
+    try {
+      const fd = new FormData();
+      fd.append("file", file);
+      fd.append("account_id", accountId);
+      const res = await api.documentPreview(fd);
+      setRows(res.rows.map((r) => ({ ...r })));
+      setDocText(res.text || "");
+    } catch (e) { toast(e.message, "error"); } finally { setBusy(false); }
+  }
+
   async function commit() {
     setBusy(true);
     try {
@@ -168,7 +183,15 @@ export default function Import() {
 
   return (
     <div>
-      <h1>{t("import.title")}</h1>
+      <div className="page-head">
+        <h1>{t("import.title")}</h1>
+        <div className="seg" style={{ width: 240, marginBottom: 0 }}>
+          <button type="button" className={`seg-btn${mode === "csv" ? " active" : ""}`}
+                  onClick={() => { setMode("csv"); setRows(null); setRaw(null); setDocText(""); }}>{t("import.modeCsv")}</button>
+          <button type="button" className={`seg-btn${mode === "doc" ? " active" : ""}`}
+                  onClick={() => { setMode("doc"); setRows(null); setRaw(null); setDocText(""); }}>{t("import.modeDoc")}</button>
+        </div>
+      </div>
 
       {/* Schritt 1: Konto + Datei */}
       <div className="card">
@@ -182,11 +205,20 @@ export default function Import() {
           </label>
           <label className="grow">
             <span>{t("import.file")}</span>
-            <input ref={fileRef} type="file" accept=".csv,text/csv,text/plain"
-                   onChange={(e) => { setFile(e.target.files?.[0] || null); setRaw(null); setRows(null); }} />
+            <input ref={fileRef} type="file"
+                   accept={mode === "doc" ? ".pdf,application/pdf,image/*" : ".csv,text/csv,text/plain"}
+                   onChange={(e) => { setFile(e.target.files?.[0] || null); setRaw(null); setRows(null); setDocText(""); }} />
           </label>
         </div>
-        <div className="row">
+        {mode === "doc" && (
+          <>
+            <button className="btn primary" onClick={loadDoc} disabled={busy || !file}>
+              <Icon name="search" size={15} /> {t("import.readDoc")}
+            </button>
+            <p className="muted small" style={{ marginTop: "var(--sp-2)" }}>{t("import.docHint")}</p>
+          </>
+        )}
+        <div className="row" style={{ display: mode === "csv" ? undefined : "none" }}>
           {presets.length > 0 && (
             <label className="grow">
               <span>{t("import.preset")}</span>
@@ -208,7 +240,8 @@ export default function Import() {
         </div>
       </div>
 
-      {/* Schritt 2: Format */}
+      {/* Schritt 2: Format (nur CSV) */}
+      {mode === "csv" && (
       <div className="card">
         <h2>{t("import.step2")}</h2>
         <div className="row">
@@ -266,6 +299,17 @@ export default function Import() {
           <Icon name="search" size={15} /> {t("import.readFile")}
         </button>
       </div>
+      )}
+
+      {/* Extrahierter Text (PDF/Bild) */}
+      {mode === "doc" && docText && (
+        <div className="card">
+          <details>
+            <summary className="muted">{t("import.extractedText")}</summary>
+            <pre className="doc-text">{docText}</pre>
+          </details>
+        </div>
+      )}
 
       {/* Schritt 3: Spaltenzuordnung */}
       {raw && (