feat(pos/facturapi): finalize Horux-to-Facturapi migration

- Normalize Facturapi key/org_id resolution (supports both cfdi_ prefixed
  tenant_config keys and short names used by invoicing_bp).
- Add CSD upload end-to-end (backend + frontend).
- Add helper scripts: setup_facturapi_orgs.py and check_facturapi_tenants.py.
- Add 20 unit tests with mocks (pos/tests/test_facturapi_service.py).
- Add CI workflow for lint + console tests on Python 3.11/3.13.
- Add pyproject.toml and requirements-dev.txt with ruff/pytest config.
- Update FASES_IMPLEMENTADAS.md with FASE 8 documentation.

Tests: 81 passing (61 console + 20 Facturapi).

pos/static/js/invoicing.js

@@ -329,6 +329,73 @@ const Invoicing = (() => {
         }
     }
 
+    function resetCsdForm() {
+        document.getElementById('csd-form').reset();
+        document.getElementById('csd-cer-label').textContent = 'Subir certificado .cer';
+        document.getElementById('csd-key-label').textContent = 'Subir llave privada .key';
+    }
+
+    function updateFileLabels() {
+        const cer = document.getElementById('csd-cer');
+        const key = document.getElementById('csd-key');
+        if (cer && cer.files.length) {
+            document.getElementById('csd-cer-label').textContent = cer.files[0].name;
+        }
+        if (key && key.files.length) {
+            document.getElementById('csd-key-label').textContent = key.files[0].name;
+        }
+    }
+
+    async function uploadCsd(btn) {
+        if (!btn) return;
+        const cer = document.getElementById('csd-cer');
+        const key = document.getElementById('csd-key');
+        const password = document.getElementById('contrasena-csd').value.trim();
+
+        if (!cer || !cer.files.length || !key || !key.files.length) {
+            alert('Selecciona el archivo .cer y .key');
+            return;
+        }
+        if (!password) {
+            alert('Escribe la contraseña del CSD');
+            return;
+        }
+
+        const formData = new FormData();
+        formData.append('certificate', cer.files[0]);
+        formData.append('private_key', key.files[0]);
+        formData.append('password', password);
+
+        btn.disabled = true;
+        const originalText = btn.innerHTML;
+        btn.textContent = 'Subiendo...';
+        try {
+            const res = await fetch(`${API}/facturapi/csd`, {
+                method: 'POST',
+                headers: { 'Authorization': `Bearer ${token()}` },
+                body: formData,
+            });
+            const data = await res.json().catch(() => ({ error: res.statusText }));
+            if (!res.ok) throw new Error(data.error || 'Upload failed');
+            alert('CSD actualizado correctamente');
+            resetCsdForm();
+            loadFacturapiStatus();
+        } catch (e) {
+            alert('Error al subir CSD: ' + e.message);
+        } finally {
+            btn.disabled = false;
+            btn.innerHTML = originalText;
+        }
+    }
+
+    // Wire file input change listeners
+    setTimeout(() => {
+        const cer = document.getElementById('csd-cer');
+        const key = document.getElementById('csd-key');
+        if (cer) cer.addEventListener('change', updateFileLabels);
+        if (key) key.addEventListener('change', updateFileLabels);
+    }, 0);
+
     // ---- Detail modal (uses modalDetalleOverlay) ----
     async function showDetail(cfdiId) {
         const overlay = document.getElementById('modalDetalleOverlay');
@@ -612,6 +679,7 @@ const Invoicing = (() => {
         showDetail, showCancelModal, confirmCancel, processQueue,
         showNewInvoiceModal, closeNewInvoiceModal, submitNewInvoice, notaCreditoPlaceholder,
         openGlobalInvoiceModal, previewGlobalInvoice, generateGlobalInvoice, setupFacturapi,
+        uploadCsd, resetCsdForm,
     };
     // Register Cmd+K items
     if (typeof registerCmdKItem === "function") {