feat(sources): PDF-Upload als neuer Quellentyp pdf_document

- POST /api/sources/global/upload-pdf: multipart File-Upload,
  50 MB Limit, SHA256-Dedup, speichert PDF unter <dirname(DB)>/pdfs/{sha}.pdf,
  legt Source mit processed_at=NULL an (Monitor verarbeitet asynchron)
- pattern in GlobalSourceUpdate um pdf_document erweitert (2x)
- dashboard.html: Button + Modal im Grundquellen-Sub-Tab
- sources.js: openPdfUploadModal + setupPdfUploadForm + FormData-Submit
- app.js: API.upload(path, formData) Helper fuer multipart
- requirements.txt: pypdf (Validierung optional)

src/static/js/sources.js

@@ -311,6 +311,8 @@ function editGlobalSource(id) {
 
 function setupSourceForms() {
   document.getElementById("newGlobalSourceBtn").addEventListener("click", openNewGlobalSource);
+  document.getElementById("newPdfSourceBtn")?.addEventListener("click", openPdfUploadModal);
+  setupPdfUploadForm();
   document.getElementById("discoverSourceBtn").addEventListener("click", () => {
     document.getElementById("discoverUrl").value = "";
     document.getElementById("discoverStatus").style.display = "none";
@@ -880,3 +882,68 @@ function toggleSourceInfo(id) {
     if (btn) btn.classList.toggle("active", !isVisible);
   }
 }
+
+// --- PDF-Quellen-Upload ---
+function openPdfUploadModal() {
+  const form = document.getElementById("pdfUploadForm");
+  if (form) form.reset();
+  const err = document.getElementById("pdfUploadError");
+  if (err) { err.style.display = "none"; err.textContent = ""; }
+  const prog = document.getElementById("pdfUploadProgress");
+  if (prog) prog.style.display = "none";
+  openModal("modalPdfUpload");
+}
+
+function setupPdfUploadForm() {
+  const form = document.getElementById("pdfUploadForm");
+  if (!form || form.dataset.bound === "1") return;
+  form.dataset.bound = "1";
+
+  form.addEventListener("submit", async (e) => {
+    e.preventDefault();
+    const errEl = document.getElementById("pdfUploadError");
+    const progEl = document.getElementById("pdfUploadProgress");
+    const submitBtn = document.getElementById("pdfUploadSubmitBtn");
+    errEl.style.display = "none";
+
+    const fileInput = document.getElementById("pdfFile");
+    const f = fileInput?.files?.[0];
+    if (!f) {
+      errEl.textContent = "Bitte eine PDF-Datei auswaehlen.";
+      errEl.style.display = "block";
+      return;
+    }
+    if (f.size > 50 * 1024 * 1024) {
+      errEl.textContent = "Datei ueberschreitet 50 MB.";
+      errEl.style.display = "block";
+      return;
+    }
+
+    const fd = new FormData();
+    fd.append("file", f);
+    const nm = document.getElementById("pdfName").value.trim();
+    if (nm) fd.append("name", nm);
+    fd.append("category", document.getElementById("pdfCategory").value || "sonstige");
+    const lng = document.getElementById("pdfLanguage").value.trim();
+    if (lng) fd.append("language", lng);
+    const nt = document.getElementById("pdfNotes").value.trim();
+    if (nt) fd.append("notes", nt);
+
+    submitBtn.disabled = true;
+    progEl.style.display = "block";
+    try {
+      await API.upload("/api/sources/global/upload-pdf", fd);
+      closeModal("modalPdfUpload");
+      if (typeof showToast === "function") {
+        showToast("PDF hochgeladen -- Verarbeitung laeuft im Hintergrund", "success");
+      }
+      loadGlobalSources();
+    } catch (err) {
+      errEl.textContent = err.message || "Upload fehlgeschlagen";
+      errEl.style.display = "block";
+    } finally {
+      submitBtn.disabled = false;
+      progEl.style.display = "none";
+    }
+  });
+}