Remove Add Transaction feature and clean all related code

Deleted files:
- AddTransactionView.swift
- TransactionRepository.swift
- Transaction+CoreDataClass.swift

Cleaned files:
- SourceDetailViewModel: removed transactions published property,
  showingAddTransaction flag, transactionRepository dependency,
  addTransaction() and deleteTransaction() methods
- SourceDetailView: removed transactionsSection, TransactionRow struct,
  Add Transaction button from quickActions, sheet presentation
- InvestmentSource+CoreDataClass: removed transactions NSManaged property,
  transactionsArray, totalInvested, totalDividends, totalFees computed
  properties, and all transaction Core Data accessors
- SettingsViewModel: removed "Transaction" from resetAllData entity list
- SampleDataService: removed transactionRepository and sample transaction

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

PortfolioJournal/Views/Goals/GoalEditorView.swift

@@ -106,13 +106,31 @@ struct GoalEditorView: View {
 
     private func parseDecimal(_ value: String) -> Decimal? {
         let locale = CurrencyFormatter.locale(for: currencyCode)
-        let cleaned = value
+        let stripped = value
             .replacingOccurrences(of: currencySymbol, with: "")
-            .replacingOccurrences(of: locale.groupingSeparator ?? "", with: "")
             .trimmingCharacters(in: .whitespaces)
 
-        guard !cleaned.isEmpty else { return nil }
+        guard !stripped.isEmpty else { return nil }
 
+        let decimalSep = locale.decimalSeparator ?? "."
+        let groupingSep = locale.groupingSeparator ?? ""
+
+        // Detect alternate decimal BEFORE removing separators
+        let usesAlternateDecimal =
+            (decimalSep == "," && stripped.contains(".") && !stripped.contains(",")) ||
+            (decimalSep == "." && stripped.contains(",") && !stripped.contains("."))
+
+        if usesAlternateDecimal {
+            let normalized = stripped
+                .replacingOccurrences(of: groupingSep, with: "")
+                .replacingOccurrences(of: ",", with: ".")
+            let formatter = NumberFormatter()
+            formatter.numberStyle = .decimal
+            formatter.locale = Locale(identifier: "en_US_POSIX")
+            return formatter.number(from: normalized)?.decimalValue
+        }
+
+        let cleaned = stripped.replacingOccurrences(of: groupingSep, with: "")
         let formatter = NumberFormatter()
         formatter.numberStyle = .decimal
         formatter.locale = locale
@@ -123,7 +141,7 @@ struct GoalEditorView: View {
 
         // Fallback for mixed locale input
         let normalized = cleaned
-            .replacingOccurrences(of: locale.decimalSeparator ?? ",", with: ".")
+            .replacingOccurrences(of: decimalSep, with: ".")
             .replacingOccurrences(of: ",", with: ".")
         formatter.locale = Locale(identifier: "en_US_POSIX")
         return formatter.number(from: normalized)?.decimalValue