feat(investment): Daily Script Master, market rate on purchase, broken-period interest as expense

- 09 Daily Script Master now saves to and loads from the backend (sample
  rows removed), with Drop to correct a wrong rate.
- Purchase Entry takes the rate (NAV for a mutual fund) from the newest
  Daily Script Master rate on or before the deal date, shows which rate
  was used, warns when the rate entered is outside the day's low-high,
  and clears the rate when the script has none.
- Broken-period interest paid to the seller is debited to expense GL
  500606 instead of Interest Receivable (RBI UCB Investment Directions,
  para 152, confirmed by Jitendra Sir); Interest Entry labels it so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/investment/bond-investment/bond-investment.component.ts

@@ -29,6 +29,7 @@ import {
   INVESTMENT_GL_BY_TYPE,
   INVESTMENT_GL_LOOKUP,
   INTEREST_RECEIVABLE_GL,
+  BROKEN_PERIOD_INTEREST_GL,
   STAMP_DUTY_GL,
   BROKERAGE_GL,
   OTHER_CHARGES_GL,
@@ -54,6 +55,7 @@ import {
 } from '../investment-data';
 import { exportWorkbook } from '../investment-export';
 import {
+  InvestmentDailyRateDto,
   InvestmentInterestScheduleDto,
   InvestmentPurchaseDto,
   InvestmentService,
@@ -391,6 +393,7 @@ export class BondInvestmentComponent implements OnInit {
     const type = this.bondType ?? 'GOVT_SECURITY';
     this.showMoreDetails = false;
     this.retrieveCertNo = '';
+    this.purchaseMarketRate = undefined;
     return {
       bondType: type,
       dealNo: this.nextDealNo(),
@@ -598,6 +601,7 @@ export class BondInvestmentComponent implements OnInit {
   /** Re-suggests the last coupon date when the deal date changes. */
   onDealDateChange(): void {
     this.suggestLastIntDate();
+    this.loadMarketRate();
   }
 
   private suggestLastIntDate(): void {
@@ -672,6 +676,46 @@ export class BondInvestmentComponent implements OnInit {
       f.productName = s.scriptName;
     }
     this.suggestLastIntDate();
+    this.loadMarketRate();
+  }
+
+  /**
+   * Market rate of the script for the deal date from the Daily Script Master (newest rate on or before it). It fills
+   * the purchase rate (NAV for a mutual fund); the dealer may still change it. undefined = not looked up yet,
+   * null = no rate entered for the script.
+   */
+  purchaseMarketRate: InvestmentDailyRateDto | null | undefined;
+
+  private loadMarketRate(): void {
+    const s = this.purchaseScript;
+    const f = this.purchaseForm;
+    if (!s?.id || !f.dealDate) {
+      this.purchaseMarketRate = undefined;
+      return;
+    }
+    this.investmentService.getLatestDailyRate(s.id, f.dealDate).subscribe({
+      next: (rate) => {
+        this.purchaseMarketRate = rate;
+        // No market rate: clear the field rather than leave another script's rate in it.
+        if (this.isMutualFund) {
+          f.nav = rate ? rate.closeRate : null;
+        } else {
+          f.purchaseRate = rate ? rate.closeRate : null;
+        }
+      },
+      error: (err) => this.toast(`Could not read the market rate: ${apiErrorMessage(err)}`)
+    });
+  }
+
+  /** True when the rate entered is outside the day's low–high in the Daily Script Master. */
+  get purchaseRateOutOfRange(): boolean {
+    const m = this.purchaseMarketRate;
+    const f = this.purchaseForm;
+    const rate = this.isMutualFund ? f.nav : f.purchaseRate;
+    if (!m || rate == null) {
+      return false;
+    }
+    return (m.lowRate != null && rate < m.lowRate) || (m.highRate != null && rate > m.highRate);
   }
 
   /** Settlement Date = Deal Date + T+n days (greyed / auto in the existing CBS). */
@@ -709,11 +753,12 @@ export class BondInvestmentComponent implements OnInit {
     const invGl = this.purchaseInvestmentGlCode;
     const lines: AccountingPreviewLine[] = [
       { side: 'Dr', glCode: invGl, glName: this.glNameOf(invGl), amount: book }];
+    // Broken-period interest paid to the seller is an expense (RBI para 152, confirmed by Jitendra Sir).
     if (accrued > 0) {
       lines.push({
         side: 'Dr',
-        glCode: INTEREST_RECEIVABLE_GL.glCode,
-        glName: INTEREST_RECEIVABLE_GL.glName,
+        glCode: BROKEN_PERIOD_INTEREST_GL.glCode,
+        glName: BROKEN_PERIOD_INTEREST_GL.glName,
         amount: accrued
       });
     }