feat(documents-wizard): replace UUID-paste fields with searchable pickers + inline upload

Reps no longer have to copy/paste UUIDs into the New-document wizard.

Three UUID inputs replaced:
- Template id Input → DocumentTemplatePicker (queries /api/v1/document-templates
  with name search; filters to isActive=true)
- Uploaded file id Input → inline FileUploadZone (drop or browse PDF; surfaces
  the uploaded file id directly to the wizard via the new onUploadComplete
  signature)
- Subject id Input → conditional picker: ClientPicker / CompanyPicker /
  YachtPicker / InterestPicker depending on the subject-type dropdown.
  Reservation falls back to Input for now (no ReservationPicker yet).

Other polish in the wizard:
- SIGNER_ROLES labels capitalized in the role select (client → Client, etc.)
  via a formatSignerRole() helper. Internal values stay lowercase.
- Pinned h-9 on Select triggers so the type/subject row + signer-role select
  vertically align with their adjacent inputs.
- Subject-type change now resets subjectId — picker options are type-specific
  and a stale id from a different entity table would be invalid.

Infrastructure for hub uploads (will be consumed in a follow-up dropdown +
drag-drop pass):
- /api/v1/files/upload route now parses folderId from FormData (schema
  already supported it).
- FileUploadZone accepts a folderId prop and forwards it, plus a new
  onUploadComplete(file) callback shape that surfaces { id, filename } on
  each successful upload. Existing per-entity callers (Files tab on clients,
  companies, yachts, interests) ignore the arg, no behaviour change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/files/file-upload-zone.tsx

@@ -18,7 +18,17 @@ interface FileUploadZoneProps {
   clientId?: string;
   yachtId?: string;
   companyId?: string;
-  onUploadComplete?: () => void;
+  /**
+   * Optional folder to deposit the file into. Hub uploads pass the
+   * currently-selected folderId so files land where the user expects.
+   */
+  folderId?: string | null;
+  /**
+   * Fires per successful upload with the file metadata. The wizard /
+   * inline-upload flows use the returned id to wire follow-up actions
+   * (e.g. set as the source PDF for a Documenso signing flow).
+   */
+  onUploadComplete?: (file?: { id: string; filename?: string }) => void;
 }
 
 export function FileUploadZone({
@@ -27,6 +37,7 @@ export function FileUploadZone({
   clientId,
   yachtId,
   companyId,
+  folderId,
   onUploadComplete,
 }: FileUploadZoneProps) {
   const [isDragOver, setIsDragOver] = useState(false);
@@ -54,6 +65,7 @@ export function FileUploadZone({
             if (companyId) formData.append('companyId', companyId);
             if (entityType) formData.append('entityType', entityType);
             if (entityId) formData.append('entityId', entityId);
+            if (folderId) formData.append('folderId', folderId);
 
             setUploading((prev) =>
               prev.map((u) => (u.id === uploadId ? { ...u, progress: 50 } : u)),
@@ -73,6 +85,16 @@ export function FileUploadZone({
               throw new Error('Upload failed');
             }
 
+            const uploadJson = (await uploadRes
+              .json()
+              .catch(() => null)) as { data?: { id?: string; filename?: string } } | null;
+            if (uploadJson?.data?.id) {
+              onUploadComplete?.({
+                id: uploadJson.data.id,
+                filename: uploadJson.data.filename,
+              });
+            }
+
             setUploading((prev) =>
               prev.map((u) => (u.id === uploadId ? { ...u, progress: 100 } : u)),
             );
@@ -90,7 +112,7 @@ export function FileUploadZone({
         onUploadComplete?.();
       }, 1500);
     },
-    [clientId, yachtId, companyId, entityType, entityId, onUploadComplete],
+    [clientId, yachtId, companyId, entityType, entityId, folderId, onUploadComplete],
   );
 
   const handleDrop = useCallback(