feat: NAS storage for invoices/offers, code cleanup, date/time fixes

- NAS storage for created invoices (PDF via puppeteer), received invoices,
  and offers with auto-save on create/edit
- Deterministic file paths derived from DB fields (no file_path column needed)
- Separate NAS mount points: NAS_FINANCIALS_PATH, NAS_OFFERS_PATH
- Invoice language field (cs/en) stored per invoice, replaces lang modal
- Invoices list filtered by month/year matching KPI card selection
- Centralized date helpers (src/utils/date.ts) replacing all .toISOString()
  calls that returned UTC instead of local time
- Attendance project switching uses exact time (not rounded)
- Comment cleanup: removed ~100 unnecessary/Czech comments
- Removed as-any casts in orders and attendance
- Prisma migrations: add invoice language, drop received_invoices BLOB columns

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/routes/admin/invoices.ts

@@ -1,4 +1,5 @@
 import { FastifyInstance } from "fastify";
+import prisma from "../../config/database";
 import { requirePermission } from "../../middleware/auth";
 import { logAudit } from "../../services/audit";
 import { success, error, parseId } from "../../utils/response";
@@ -19,6 +20,7 @@ import {
   updateInvoice,
   deleteInvoice,
 } from "../../services/invoices.service";
+import { nasFinancialsManager } from "../../services/nas-financials-manager";
 
 export default async function invoicesRoutes(
   fastify: FastifyInstance,
@@ -46,6 +48,8 @@ export default async function invoicesRoutes(
         search,
         status: query.status ? String(query.status) : undefined,
         customer_id: query.customer_id ? Number(query.customer_id) : undefined,
+        month: query.month ? Number(query.month) : undefined,
+        year: query.year ? Number(query.year) : undefined,
       });
 
       return reply.send({
@@ -185,6 +189,13 @@ export default async function invoicesRoutes(
       const existing = await deleteInvoice(id);
       if (!existing) return error(reply, "Faktura nenalezena", 404);
 
+      // Delete PDF from NAS
+      if (existing.invoice_number && existing.issue_date) {
+        const d = new Date(existing.issue_date);
+        const relPath = `Vydané/${d.getFullYear()}/${String(d.getMonth() + 1).padStart(2, "0")}/${existing.invoice_number}.pdf`;
+        nasFinancialsManager.deleteIssuedInvoice(relPath);
+      }
+
       await logAudit({
         request,
         authData: request.authData,
@@ -196,4 +207,33 @@ export default async function invoicesRoutes(
       return success(reply, null, 200, "Faktura smazána");
     },
   );
+
+  // GET /api/admin/invoices/:id/file — serve PDF from NAS
+  fastify.get<{ Params: { id: string } }>(
+    "/:id/file",
+    { preHandler: requirePermission("invoices.view") },
+    async (request, reply) => {
+      const id = parseId(request.params.id, reply);
+      if (id === null) return;
+      const invoice = await prisma.invoices.findUnique({
+        where: { id },
+        select: { invoice_number: true, issue_date: true },
+      });
+      if (!invoice?.invoice_number || !invoice.issue_date)
+        return error(reply, "Faktura nenalezena", 404);
+
+      const d = new Date(invoice.issue_date);
+      const relPath = `Vydané/${d.getFullYear()}/${String(d.getMonth() + 1).padStart(2, "0")}/${invoice.invoice_number}.pdf`;
+      const file = nasFinancialsManager.readIssuedInvoice(relPath);
+      if (!file) return error(reply, "PDF soubor nenalezen", 404);
+
+      return reply
+        .type("application/pdf")
+        .header(
+          "Content-Disposition",
+          `inline; filename="${invoice.invoice_number}.pdf"`,
+        )
+        .send(file.data);
+    },
+  );
 }