feat(investment,reconciliation): add Export to Excel across Investment, fix export popup

Adds a shared Export to Excel utility (investment-export.ts) and wires it
into every listing/report screen in the Investment module — Dashboard
(break-up + allocation), Reports (all ~20 report shapes), Interest (per
active tab), the FD/Bond/Share Holdings registers, and Masters (per active
master tab). Entry/transaction forms intentionally have no export button.
No sign-off is included here, matching the request to keep that feature
reconciliation-only.

Also fixes the Reconciliation export flow: the Prepared/Checked/Approved
sign-off is now an optional one-off popup shown when "Export to Excel" is
clicked (fields are blank by default and downloading works whether or not
they're filled), replacing the earlier always-visible sign-off card. Also
fixes three reconciliation reports (Sundry Dr/Cr, NEFT/RTGS, UDIR) whose
labels contain "/" — an Excel-forbidden worksheet-name character — which
was silently aborting their export.

src/app/reconciliation/reconciliation-report/reconciliation-report.component.html

@@ -51,6 +51,11 @@
         <input type="text" [(ngModel)]="asOnDate" placeholder="DD-MM-YYYY" />
       </label>
       <button type="button" class="pg-btn pg-btn--primary" (click)="generate()">Generate</button>
+      @if (!isRestricted) {
+        <button type="button" class="pg-btn pg-btn--ghost" [disabled]="generating" (click)="openExportModal()">
+          {{ generating ? 'Exporting…' : 'Export to Excel' }}
+        </button>
+      }
     </div>
   </header>
 
@@ -225,4 +230,42 @@
   }
 </div>
 
+@if (showExportModal) {
+  <div class="recon-modal-backdrop" (click)="closeExportModal()">
+    <div class="recon-modal" (click)="$event.stopPropagation()">
+      <div class="recon-modal__header">
+        <span>Export to Excel — Sign-off (Optional)</span>
+        <button type="button" class="recon-modal__close" (click)="closeExportModal()" aria-label="Close">
+          &times;
+        </button>
+      </div>
+      <p class="pg-sub" style="padding: 0 20px">
+        Fill in Prepared / Checked / Approved details if this copy needs them for the record — or leave them blank and
+        download straight away.
+      </p>
+      <div class="recon-signoff-grid">
+        <div class="recon-signoff-col">
+          <span class="recon-signoff-role">Prepared By</span>
+          <input type="text" placeholder="Name" [(ngModel)]="exportSignOff.preparedByName" />
+          <input type="text" placeholder="Designation" [(ngModel)]="exportSignOff.preparedByDesg" />
+        </div>
+        <div class="recon-signoff-col">
+          <span class="recon-signoff-role">Checked By</span>
+          <input type="text" placeholder="Name" [(ngModel)]="exportSignOff.checkedByName" />
+          <input type="text" placeholder="Designation" [(ngModel)]="exportSignOff.checkedByDesg" />
+        </div>
+        <div class="recon-signoff-col">
+          <span class="recon-signoff-role">Approved By</span>
+          <input type="text" placeholder="Name" [(ngModel)]="exportSignOff.approvedByName" />
+          <input type="text" placeholder="Designation" [(ngModel)]="exportSignOff.approvedByDesg" />
+        </div>
+      </div>
+      <div class="inv-form-actions" style="padding: 0 20px 20px">
+        <button type="button" class="pg-btn pg-btn--ghost" (click)="closeExportModal()">Cancel</button>
+        <button type="button" class="pg-btn pg-btn--primary" (click)="confirmExport()">Download</button>
+      </div>
+    </div>
+  </div>
+}
+
 <div class="inv-toast" [class.show]="toastVisible">{{ toastMsg }}</div>