feat(documents)!: unify offers and issued orders end to end

One coherent pass over the two sibling document models, driven by a 3-lens
1:1 scan (~60 divergences inventoried) + user decisions. Migration adds
issued_orders.locked_by/locked_at and the issued_order_sections table
(mirror of scope_sections; applied to dev + test DBs).

Issued orders gained (offers as reference implementation):
- rich-text SECTIONS with CZ/EN titles, rendered on their own PDF page in
  the PO template's red style (shared DocumentSectionSchema, one-transaction
  create/update incl. items - fixes a torn-write bug)
- edit LOCKING (lock/heartbeat/unlock routes, 423 + holder name, 30s TTL =
  3 missed 10s heartbeats; locked_by enrichment on detail)
- archived-PDF serving: GET /:id/file reads the NAS copy (new
  readIssuedByNumber sweep) with live-render fallback + re-archive; offers'
  /file got the same fallback (kills the 'ulozte nabidku' dead end)
- NAS cleanup on delete, in-tx po_number uniqueness (409), collision-advancing
  number previews (also invoice previews), PUT returns assigned po_number

Offers hardened (issued as reference):
- VALID_TRANSITIONS enforced (no more numberless 'ordered' offers; invalidate
  follows the table; order creation only from active offers) +
  valid_transitions on detail
- explicit 400 instead of silent edits outside draft/active (mirrored on
  issued: explicit 400 replaced silent drops)
- customer existence check + Number(null)->0 clear bug fixed; delete of a
  linked offer -> 409 instead of P2003 500; error-token convention; Zod caps
  DB-aligned (desc 500/unit 20/number 50/project_code 100, isoDateString
  dates, ints for positions); audit old/new values + koncept fallbacks;
  list id tiebreaks; stats include trimmed; NAS delete dedupe

Frontend unification (6 new shared modules):
- components/document/{DocumentItemsEditor,SectionsEditor,LockBanner}
- hooks/{useDocumentLock,useUnsavedChangesGuard,useDocumentPdf(+list variant)}
- OfferDetail 1940->1100 lines, IssuedOrderDetail 1400->980: headline-only
  document number (form field removed), one form layout/readonly convention,
  view-permission opens read-only everywhere (issued's editable-for-viewers
  hole closed), server-driven transition buttons, dirty guard + Enter submit
  on both, useApiMutation everywhere (new opt-in envelope mode), fixed
  infinite spinner on failed detail fetch, draft PDFs hidden (no number yet)
- lists: supplier filter + count line on issued, Mena column dropped + mono
  numbers on offers, shared hardened per-row PDF flow (spinner, double-click
  guard, 401 close, blob cleanup), proper Czech quotes, real CTA empty
  states, query-lib cleanups (["offers","customers"] key, typed list rows,
  shared CurrencyAmount, retry:false on details)
- pdf-shared.ts: one escapeHtml/cleanQuillHtml(strict)/formatNum(NBSP)/
  formatCurrency/formatDate for all four PDF routes; offer PDF keeps its
  monochrome look (fractional qty fix: 1.5 no longer prints as 2); issued
  PDF language now comes from the document column

+49 tests (suite 364 -> 413). Each stage passed an independent review; final
cross-stage integration review verified the FE<->BE contracts.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/services/orders.service.ts

@@ -9,6 +9,7 @@ import {
   releaseProjectNumber,
 } from "./numbering.service";
 import { NasFileManager } from "./nas-file-manager";
+import { VALID_TRANSITIONS as OFFER_VALID_TRANSITIONS } from "./offers.service";
 
 // Best-effort NAS folder creation for order-spawned projects, mirroring
 // projects.service. Stateless singleton; reads NAS_PATH at construction.
@@ -301,7 +302,7 @@ export async function createOrderFromQuotation(
     where: { id: quotationId },
     include: {
       quotation_items: { orderBy: { position: "asc" } },
-      scope_sections: { orderBy: { position: "asc" } },
+      scope_sections: { orderBy: [{ position: "asc" }, { id: "asc" }] },
     },
   });
 
@@ -312,6 +313,19 @@ export async function createOrderFromQuotation(
       status: 400,
     } as const;
 
+  // The flow sets the offer's status to `ordered`, so it must respect the
+  // offers transition table: only an offer whose current status allows the
+  // `ordered` transition qualifies. A draft must be finalized first (it has no
+  // number yet — an ordered offer without a number must never exist) and an
+  // invalidated offer is terminal.
+  const allowedFromStatus = OFFER_VALID_TRANSITIONS[quotation.status] || [];
+  if (!allowedFromStatus.includes("ordered")) {
+    return {
+      error: `Objednávku nelze vytvořit z nabídky ve stavu "${quotation.status}"`,
+      status: 400,
+    } as const;
+  }
+
   const result = await prisma.$transaction(async (tx) => {
     const orderNumber = await generateSharedNumber(tx);
     // The order keeps the shared (order) sequence; the auto-created project