feat: cashier denomination-wise opening & closing balance panels in all deposit/withdrawal forms

OVERVIEW
--------
Added real-time cashier cash position display inside the denomination breakdown
panel of all 4 transaction entry screens: Savings, Current Account, Recurring
Deposit, and Fixed Deposit. Shows opening balance at the top and projected
closing balance at the bottom after factoring in the current transaction.

BACKEND INTEGRATION
-------------------
- New CashierService (src/app/cashier/cashier.service.ts)
  getCashierPositionForMe(asOfDate?) calls GET /cashreports/cashier-position/me
  Returns denomination-wise opening cash position for the logged-in cashier user.
  Non-cashier users receive empty denominations array; UI hides panels silently.

OPENING BALANCE CARD (top of denomination panel)
-------------------------------------------------
- Loaded on ngOnInit() via loadOpeningPosition() in all 4 component .ts files
- Notes and Coins displayed in separate labeled pill sections
- Each pill shows: Rs{value} x{count} format
- Card is hidden entirely if the logged-in user is not a cashier

CLOSING BALANCE CARD (below tally / Apply button)
--------------------------------------------------
- Computed getter closingDenoms() merges opening position with entered denominations
  deposit:    closingCount = openCount + enteredCount
  withdrawal: closingCount = openCount - enteredCount
- Notes and Coins in separate labeled pill sections (identical format to opening)
- Entered/changed denominations (delta != 0): full opacity + bold font weight
- Untouched denominations (delta = 0): 38% opacity, clearly dimmed, no borders
- closingTotal = openingTotal +/- denominationTotal shown in card header
- Card turns green for positive closing balance, red for negative

COMPONENTS UPDATED
------------------
- savings-account-transactions       (.ts / .html / .scss)
- current-account-transactions       (.ts / .html / .scss)
- deposit-recurring-deposits-account (.ts / .html / .scss)
- fixed-deposits-cash-transaction    (.ts / .html / .scss)

CASHIER MODULE (new - src/app/cashier/)
-----------------------------------------
Full cashier workspace module added to the app:
- cashier.service.ts          API calls (position, transfers, settlement, etc.)
- cashier.module.ts           Angular module declaration
- cashier-routing.module.ts   Lazy-loaded routes
- cashier-position/           Cashier cash position dashboard
- cash-exchange-entry/        Cash exchange denomination entry
- cash-history/               Transaction history per cashier
- cash-settlement/            End-of-day cash settlement
- cash-transfer/              Vault-to-cashier cash transfer
- inter-cashier-transfer/     Transfer between cashier drawers
- reconciliation/             Cash reconciliation with GL
- closing-cash-report/        Closing balance report
- currency-exchange-detail/   Currency exchange breakdown
- excess-transaction-report/  Excess/short transaction report
Module wired into app.module.ts and shell nav (shell.component.html).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/app.module.ts

@@ -39,6 +39,7 @@ import { AccountingModule } from './accounting/accounting.module';
 import { SystemModule } from './system/system.module';
 import { ProductsModule } from './products/products.module';
 import { OrganizationModule } from './organization/organization.module';
+import { CashierModule } from './cashier/cashier.module';
 import { TemplatesModule } from './templates/templates.module';
 import { UsersModule } from './users/users.module';
 import { ReportsModule } from './reports/reports.module';
@@ -143,6 +144,7 @@ export function HttpLoaderFactory(http: HttpClient) {
     SystemModule,
     ProductsModule,
     OrganizationModule,
+    CashierModule,
     TemplatesModule,
     UsersModule,
     NotificationsModule,