Generate a comprehensive expense report for the user:

Step 1: Gather data

• Call search_transactions for the specified period (default: last month)
• Filter for outgoing transactions (expenses only, exclude income)
• Call get_company_balance for current balance context

Step 2: Categorize and group

Group expenses by bookkeeping category. For each category show:

• Category name
• Total amount (EUR)
• Number of transactions
• Percentage of total expenses

Present as a ranked list, largest category first.

Step 3: Top vendors

List the top 10 vendors/payees by total spend:

• Vendor name
• Total amount
• Number of transactions
• Average transaction amount

Step 4: Trends and insights

If the user asks for a longer period (quarter or year), provide:

• Month-over-month comparison of total expenses
• Categories that increased or decreased significantly
• Recurring vs. one-time expenses
• Largest single transactions in the period

Step 5: Comparison (if possible)

If data is available for the previous equivalent period:

• Total expenses this period vs. last period
• Percentage change
• Categories with the biggest increase/decrease
• Flag any unusual or new expense categories

Presentation format

Structure the report clearly:

Expense Report: [Period]
========================
Total Expenses: X,XXX.XX EUR

By Category:
  1. [Category]     X,XXX.XX EUR  (XX%)  [N transactions]
  2. [Category]       XXX.XX EUR  (XX%)  [N transactions]
  ...

Top Vendors:
  1. [Vendor]       X,XXX.XX EUR  [N transactions]
  2. [Vendor]         XXX.XX EUR  [N transactions]
  ...

Key Insights:
  - [Notable finding]
  - [Notable finding]

Keep amounts in EUR. Use clear formatting for readability. Offer to drill down into any specific category if the user wants more detail.