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/investment-masters/investment-masters.component.ts

@@ -17,7 +17,6 @@ import {
   MUTUAL_FUND_PRODUCTS,
   SGL_BANK_MASTER,
   SCRIPT_MARKET_DETAIL,
-  DAILY_SCRIPT_RATES,
   LIEN_REASON_MASTER,
   ScriptMaster,
   BrokerMaster,
@@ -36,7 +35,7 @@ import {
   periodBetween
 } from '../investment-data';
 import { exportWorkbook, ExportSheetSpec } from '../investment-export';
-import { InvestmentGlAccount, InvestmentService, apiErrorMessage } from '../investment.service';
+import { InvestmentGlAccount, InvestmentService, apiErrorMessage, toDailyScriptRate } from '../investment.service';
 
 type MasterTab =
   | 'party'
@@ -79,7 +78,8 @@ export class InvestmentMastersComponent implements OnInit {
   mfProducts: MutualFundProductMaster[] = [...MUTUAL_FUND_PRODUCTS];
   sglBanks: SglBankMaster[] = [...SGL_BANK_MASTER];
   marketDetails: ScriptMarketDetail[] = [...SCRIPT_MARKET_DETAIL];
-  dailyScriptRates: DailyScriptRate[] = [...DAILY_SCRIPT_RATES];
+  /** Loaded from the backend (Daily Script Master) in ngOnInit. */
+  dailyScriptRates: DailyScriptRate[] = [];
   lienReasons: LienReason[] = [...LIEN_REASON_MASTER];
 
   readonly instrumentTypes: InstrumentType[] = [
@@ -131,6 +131,7 @@ export class InvestmentMastersComponent implements OnInit {
   newDailyRate: Partial<DailyScriptRate> = {};
 
   ngOnInit(): void {
+    this.loadDailyRates();
     this.investmentService.getAssetGlAccounts().subscribe({
       next: (gls) => (this.investmentGlOptions = gls),
       error: (err) => this.toast(`Could not load GL accounts: ${apiErrorMessage(err)}`)
@@ -435,24 +436,56 @@ export class InvestmentMastersComponent implements OnInit {
     this.toast('SGL Bank master added.');
   }
 
+  private loadDailyRates(): void {
+    this.investmentService.getDailyRates().subscribe({
+      next: (rows) => (this.dailyScriptRates = rows.map(toDailyScriptRate)),
+      error: (err) => this.toast(`Could not load daily script rates: ${apiErrorMessage(err)}`)
+    });
+  }
+
   addDailyRate(): void {
-    if (!this.newDailyRate.scriptCode || !this.newDailyRate.rateDate || this.newDailyRate.closeRate == null) {
+    const r = this.newDailyRate;
+    if (!r.scriptCode || !r.rateDate || r.closeRate == null) {
       this.toast('Enter Rate Date, Script Code and Close Rate.');
       return;
     }
-    const script = this.scripts.find((s) => s.scriptCode === this.newDailyRate.scriptCode);
-    this.dailyScriptRates = [
-      {
-        scriptName: script?.scriptName || '',
-        openRate: this.newDailyRate.closeRate,
-        highRate: this.newDailyRate.closeRate,
-        lowRate: this.newDailyRate.closeRate,
-        ...this.newDailyRate
-      } as DailyScriptRate,
-      ...this.dailyScriptRates
-    ];
-    this.newDailyRate = {};
-    this.toast('Daily script rate added.');
+    const script = this.scripts.find((s) => s.scriptCode === r.scriptCode);
+    if (!script?.id) {
+      this.toast(`Script ${r.scriptCode} is not saved in Script Master.`);
+      return;
+    }
+    const body = {
+      scriptId: script.id,
+      rateDate: r.rateDate,
+      closeRate: r.closeRate,
+      ...(r.openRate != null ? { openRate: r.openRate } : {}),
+      ...(r.highRate != null ? { highRate: r.highRate } : {}),
+      ...(r.lowRate != null ? { lowRate: r.lowRate } : {}),
+      dateFormat: 'dd-MM-yyyy',
+      locale: 'en'
+    };
+    this.investmentService.createDailyRate(body).subscribe({
+      next: () => {
+        this.toast(`Rate for ${r.scriptCode} on ${r.rateDate} saved.`);
+        this.newDailyRate = {};
+        this.loadDailyRates();
+      },
+      error: (err) => this.toast(apiErrorMessage(err))
+    });
+  }
+
+  /** A wrong rate is corrected by dropping it and entering it again. */
+  dropDailyRate(r: DailyScriptRate): void {
+    if (!r.id) {
+      return;
+    }
+    this.investmentService.deleteDailyRate(r.id).subscribe({
+      next: () => {
+        this.toast(`Rate for ${r.scriptCode} on ${r.rateDate} dropped.`);
+        this.loadDailyRates();
+      },
+      error: (err) => this.toast(apiErrorMessage(err))
+    });
   }
 
   // -------------------- Export to Excel --------------------