feat(investment): add Treasury Investment module (FD, Govt Sec/Non-SLR/Bond/MF, Share)

Adds full frontend-only Investment module mirroring the legacy AutoBank CBS
Investment menu: Dashboard, FD/Bond/Share entry screens (purchase, interest,
sell/redeem, write-off, amortize and more), 10 master screens, an Interest
calculation/register screen, and ~21 reports. All figures are derived from a
single holdings/transactions dataset so entry, interest, and reports can
never drift out of sync. Wires the new "Investment" mega-menu into the shell
and routes the previously inert Investment stub buttons.

src/app/app.module.ts

@@ -65,6 +65,7 @@ import { DeafModule } from './deaf/deaf.module';
 import { DicgcModule } from './dicgc/dicgc.module';
 import { FiuModule } from './fiu/fiu.module';
 import { SftModule } from './sft/sft.module';
+import { InvestmentModule } from './investment/investment.module';
 import { DigitalModule } from './digital/digital.module';
 import { LetterMgmtModule } from './letter-mgmt/letter-mgmt.module';
 import { AccountsModule } from './accounts/accounts.module';
@@ -172,6 +173,7 @@ export function HttpLoaderFactory(http: HttpClient) {
     DicgcModule,
     FiuModule,
     SftModule,
+    InvestmentModule,
     DigitalModule,
     LetterMgmtModule,
     AccountsModule,