fix(wizard,quotes,dates): reliable error routing, single-project accept, Persian date/time input

Wizard:
- failed saves now route to the exact step+field: a new data-field attribute on every required section (supplier_id, line_items, termsheets, project, quote_date, expiry_date, notes, proforma) plus resolveErrorTarget() that maps ApiError.field / message keywords (supplier, line item/material/unit/quantity, termsheet/schedule/milestone, project, dates, notes, file) to the offending step — the «رفع خطا» toast action scrolls/focuses the right control instead of guessing
- material records are no longer created on the fly while typing (rememberMaterial no longer fires addMaterial per blur); materials/specs/units are written once during the final save, avoiding half-created catalog rows

Accept flow:
- quote_service no longer rewrites LineItemProjects on accept — those candidate-project rows stay 100% untouched and only item_decisions.project_id is written, matching the per-item target-project model and the UI payload (item_projects: [])

Dates/time:
- JalaliDatePicker: hour/minute are now editable text fields (Persian digits, clamping, 3-digit retype handling) with a controlled useEffect that only rewrites the inputs when the numeric value actually changes — no more wiping in-progress typing; date-only detection tightened to a full YYYY-MM-DD match so datetime strings are not misread

Also: /api validation logging (RequestValidationError) now includes the path and error list for faster diagnosis.

Verified: api + frontend image builds (python, tsc, vite) clean on top of origin/production (incl. the team's mobile layout merges).

frontend/src/pages/Dashboard/EditModal.tsx

@@ -37,6 +37,7 @@ import {
 interface EditItemRow {
   key: string;
   origLi?: LineItem;
+  projects?: { id: string; name: string }[];
   cat: string;
   brand: string;
   specs: string[];
@@ -148,7 +149,17 @@ export function EditModal({ quoteId, onClose }: EditModalProps) {
     if (!q) return;
     const sup = supplierById(suppliers, q.supplier_id);
     setSupplierName(sup.name);
-    setSelectedProjects(q.projects && q.projects.length ? [...q.projects] : q.project ? [q.project] : []);
+    // حفظ تمام پروژه‌های کاندیدا: اتحاد پروژه‌های سطح پیشنهاد و پروژه‌های کاندیدای هر قلم
+    const candidateSet = new Set<string>();
+    (q.projects || []).forEach((p) => p && candidateSet.add(p));
+    if (q.project) candidateSet.add(q.project);
+    q.line_items.forEach((li) => {
+      (li.projects || []).forEach((p) => {
+        const n = typeof p === "string" ? p : p.name;
+        if (n) candidateSet.add(n);
+      });
+    });
+    setSelectedProjects([...candidateSet]);
     setNotes(q.notes || "");
     setItemRows(
       q.line_items.map((li) => {
@@ -156,6 +167,7 @@ export function EditModal({ quoteId, onClose }: EditModalProps) {
         return {
           key: li.id,
           origLi: li,
+          projects: li.projects && li.projects.length ? [...li.projects] : [],
           cat: m.category || "",
           brand: m.brand || "",
           specs: materialSpecs(m),
@@ -349,8 +361,15 @@ export function EditModal({ quoteId, onClose }: EditModalProps) {
         acceptedTsId = null;
       }
 
+      const candProjs =
+        row.projects && row.projects.length
+          ? row.projects
+          : row.origLi?.projects && row.origLi.projects.length
+            ? row.origLi.projects
+            : selectedProjects.map((pname) => ({ id: "", name: pname }));
+
       newItems.push({
-        id: "li-" + (newItems.length + 1),
+        id: row.origLi ? row.origLi.id : row.key.startsWith("new-") ? row.key : "li-" + (newItems.length + 1),
         material_id: materialId,
         quantity: qty,
         unit,
@@ -360,7 +379,7 @@ export function EditModal({ quoteId, onClose }: EditModalProps) {
         accepted_ts_id: acceptedTsId,
         rejected,
         arrived_date: row.origLi?.arrived_date ?? null,
-        projects: row.origLi?.projects ?? [],
+        projects: candProjs,
         target_project: status === "offered" ? null : (row.origLi?.target_project ?? null),
         target_project_id: status === "offered" ? null : (row.origLi?.target_project_id ?? null),
       });