Clean up awkward "the Libra" phrasing left over from rename

Replaces entity-sense references to "the Libra" with "the
organization"/"the collective" where Libra was being used as a
stand-in for the original "Castle" entity, and drops the redundant
"(like cooperatives)" parenthetical in DOCUMENTATION.md. Also swaps
the 🏰 emoji in the import helper for ⚖️.

Closes #12

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

description.md

@@ -9,27 +9,27 @@ A comprehensive double-entry accounting system for collective projects, designed
 - **User Expense Tracking**: Members can record out-of-pocket expenses as either:
   - **Liabilities**: Libra owes them money (reimbursable)
   - **Equity**: Their contribution to the collective
-- **Accounts Receivable**: Track what users owe the Libra (e.g., accommodation fees)
+- **Accounts Receivable**: Track what users owe the organization (e.g., accommodation fees)
 - **Revenue Tracking**: Record revenue received by the collective
-- **User Balance Dashboard**: Each user sees their balance with the Libra
+- **User Balance Dashboard**: Each user sees their balance with the organization
 - **Lightning Integration**: Generate invoices for outstanding balances
 - **Transaction History**: View all accounting entries and transactions
 
 ## Use Cases
 
 ### 1. User Pays Expense Out of Pocket
-When a member buys supplies for the Libra:
+When a member buys supplies for the collective:
 - They can choose to be reimbursed (Liability)
 - Or contribute it as equity (Equity)
 
 ### 2. Accounts Receivable
-When someone stays at the Libra and owes money:
+When someone stays with the collective and owes money:
 - Admin creates an AR entry (e.g., "5 nights @ 10€/night = 50€")
 - User sees they owe 50€ in their dashboard
 - They can generate an invoice to pay it off
 
 ### 3. Revenue Recording
-When the Libra receives revenue:
+When the organization receives revenue:
 - Record revenue with the payment method (Cash, Lightning, Bank)
 - Properly categorized in the accounting system