Quality-of-life enhancements: CSV import/export, opening balances, interest rates, mobile UX

- CSV import/export for Units, Projects, and Vendors with match-on-name/number upsert
- Cash Flow report toggle for Cash Only vs Cash + Investments
- Per-account and bulk opening balance setting with as-of date
- Interest rate field on normal accounts with estimated monthly/annual interest display
- Mobile sidebar auto-close on navigation
- Shared CSV parsing/export utility extracted to frontend/src/utils/csv.ts

DB migration needed for existing tenants:
  ALTER TABLE accounts ADD COLUMN IF NOT EXISTS interest_rate DECIMAL(6,4);

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

backend/src/modules/accounts/accounts.service.ts

@@ -55,8 +55,8 @@ export class AccountsService {
     }
 
     const insertResult = await this.tenant.query(
-      `INSERT INTO accounts (account_number, name, description, account_type, fund_type, parent_account_id, is_1099_reportable)
-       VALUES ($1, $2, $3, $4, $5, $6, $7)
+      `INSERT INTO accounts (account_number, name, description, account_type, fund_type, parent_account_id, is_1099_reportable, interest_rate)
+       VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
        RETURNING id`,
       [
         dto.accountNumber,
@@ -66,6 +66,7 @@ export class AccountsService {
         dto.fundType,
         dto.parentAccountId || null,
         dto.is1099Reportable || false,
+        dto.interestRate || null,
       ],
     );
     const accountId = Array.isArray(insertResult[0]) ? insertResult[0][0].id : insertResult[0].id;
@@ -172,6 +173,7 @@ export class AccountsService {
     if (dto.is1099Reportable !== undefined) { sets.push(`is_1099_reportable = $${idx++}`); params.push(dto.is1099Reportable); }
     if (dto.isActive !== undefined) { sets.push(`is_active = $${idx++}`); params.push(dto.isActive); }
     if (dto.isPrimary !== undefined) { sets.push(`is_primary = $${idx++}`); params.push(dto.isPrimary); }
+    if (dto.interestRate !== undefined) { sets.push(`interest_rate = $${idx++}`); params.push(dto.interestRate); }
 
     if (!sets.length) return account;
 
@@ -204,7 +206,30 @@ export class AccountsService {
     return this.findOne(id);
   }
 
-  async adjustBalance(id: string, dto: { targetBalance: number; asOfDate: string; memo?: string }) {
+  async setOpeningBalance(id: string, dto: { targetBalance: number; asOfDate: string; memo?: string }) {
+    return this.adjustBalance(id, dto, 'opening_balance');
+  }
+
+  async bulkSetOpeningBalances(dto: { asOfDate: string; entries: { accountId: string; targetBalance: number }[] }) {
+    let processed = 0, skipped = 0;
+    const errors: string[] = [];
+
+    for (const entry of dto.entries) {
+      try {
+        const result = await this.setOpeningBalance(entry.accountId, {
+          targetBalance: entry.targetBalance,
+          asOfDate: dto.asOfDate,
+        });
+        if (result.message === 'No adjustment needed') skipped++;
+        else processed++;
+      } catch (err: any) {
+        errors.push(`${entry.accountId}: ${err.message}`);
+      }
+    }
+    return { processed, skipped, errors };
+  }
+
+  async adjustBalance(id: string, dto: { targetBalance: number; asOfDate: string; memo?: string }, entryType = 'adjustment') {
     const account = await this.findOne(id);
 
     // Get current balance for this account using trial balance logic
@@ -282,16 +307,20 @@ export class AccountsService {
     const equityDebit = targetCredit > 0 ? targetCredit : 0;
     const equityCredit = targetDebit > 0 ? targetDebit : 0;
 
-    const memo = dto.memo || `Balance adjustment to ${dto.targetBalance}`;
+    const defaultMemo = entryType === 'opening_balance'
+      ? `Opening balance for ${account.name}`
+      : `Balance adjustment to ${dto.targetBalance}`;
+    const memo = dto.memo || defaultMemo;
 
     // Create journal entry
     const jeRows = await this.tenant.query(
       `INSERT INTO journal_entries (entry_date, description, entry_type, fiscal_period_id, is_posted, posted_at, created_by)
-       VALUES ($1, $2, 'adjustment', $3, true, NOW(), $4)
+       VALUES ($1, $2, $3, $4, true, NOW(), $5)
        RETURNING *`,
       [
         dto.asOfDate,
         memo,
+        entryType,
         fiscalPeriodId,
         '00000000-0000-0000-0000-000000000000',
       ],