Add bank reconciliation workflow and templates

New capability for importing bank transactions (Schwab JSON), matching
against existing ledger entries, creating missing transactions, and
reconciling balances. Includes two new Grist tables (Reconciliations,
BankRules), two bank-import templates, and reference documentation.

references/workflows.md

@@ -12,6 +12,7 @@ Detailed code examples for common accounting operations.
 - [Pay Bill via Owner](#pay-bill-via-owner-reimbursement)
 - [Reimburse Owner](#reimburse-owner)
 - [Batch Operations](#batch-operations)
+- [Bank Reconciliation](#bank-reconciliation)
 
 ## Create a Vendor
 
@@ -298,5 +299,124 @@ For bank fees, minor expenses without vendor invoices:
 | 23 | 3001 | Owner's Investment |
 | 24 | 3002 | Owner's Draws |
 | 25 | 4001 | Service Revenue |
+| 26 | 4010 | Interest Income |
 | 30 | 5020 | Bank & Merchant Fees |
 | 36 | 5080 | Software & Subscriptions |
+
+## Bank Reconciliation
+
+Import bank transactions, match against ledger, create missing entries, and reconcile.
+
+For full reference: see [reconciliation.md](reconciliation.md)
+
+### Phase 1: Import Bank File (Schwab JSON)
+
+```python
+# Read and parse the bank export file
+import json
+with open("path/to/schwab_export.json") as f:
+    data = json.load(f)
+
+# Parse each PostedTransaction
+for txn in data["PostedTransactions"]:
+    # Date: "MM/DD/YYYY" -> Unix timestamp
+    # Amount: parse "$X,XXX.XX" strings; Deposit = positive, Withdrawal = negative
+    # Empty string = no amount (skip)
+    pass
+```
+
+### Phase 2: Match Against Ledger
+
+```python
+# Fetch existing TransactionLines for Checking (id=14)
+# MUST use get_records, not sql_query (Transaction is reserved word)
+get_records("TransactionLines", filter={"Account": [14]})
+
+# Get transaction details for date matching
+sql_query("SELECT id, Date, Description, Status FROM Transactions WHERE id IN (...)")
+
+# Match criteria: exact amount AND date ±3 days AND not already matched
+# Deposits match Debit > 0 (money into checking = debit to asset)
+# Withdrawals match Credit > 0 (money out of checking = credit to asset)
+```
+
+### Phase 3: Create Missing Transactions
+
+```python
+# For unmatched deposits (e.g., interest income):
+add_records("Transactions", [{
+    "Date": 1738195200,
+    "Description": "Bank interest income",
+    "Reference": "Interest Paid",
+    "Status": "Cleared",
+    "Memo": "Auto-imported from bank statement"
+}])
+# Returns: {"inserted_ids": [txn_id]}
+
+# Dr Checking, Cr Interest Income
+add_records("TransactionLines", [
+    {"Transaction": txn_id, "Account": 14, "Debit": 0.01, "Credit": 0, "Memo": "Bank interest"},
+    {"Transaction": txn_id, "Account": 26, "Debit": 0, "Credit": 0.01, "Memo": "Bank interest"}
+])
+
+# For unmatched withdrawals (e.g., ATM owner draw):
+add_records("Transactions", [{
+    "Date": 1739750400,
+    "Description": "ATM withdrawal - owner draw",
+    "Reference": "P421164 88 ESSEX STREET NEW YORK",
+    "Status": "Cleared",
+    "Memo": "Auto-imported from bank statement"
+}])
+
+# Dr Owner's Draws, Cr Checking
+add_records("TransactionLines", [
+    {"Transaction": txn_id, "Account": 24, "Debit": 102.00, "Credit": 0, "Memo": "ATM withdrawal"},
+    {"Transaction": txn_id, "Account": 14, "Debit": 0, "Credit": 102.00, "Memo": "ATM withdrawal"}
+])
+
+# Optionally save a BankRule for auto-categorization:
+add_records("BankRules", [{
+    "Account": 14,
+    "Pattern": "Interest Paid",
+    "MatchType": "Contains",
+    "OffsetAccount": 26,
+    "TransactionDescription": "Bank interest income",
+    "IsActive": true
+}])
+```
+
+### Phase 4: Reconcile
+
+```python
+# Update matched existing transactions to Cleared status
+update_records("Transactions", [
+    {"id": existing_txn_id, "fields": {"Status": "Cleared"}}
+])
+
+# Calculate cleared balance
+lines = get_records("TransactionLines", filter={"Account": [14]})
+txn_ids = list(set(l["fields"]["Transaction"] for l in lines))
+cleared = sql_query(f"SELECT id FROM Transactions WHERE Status = 'Cleared' AND id IN (...)")
+cleared_ids = set(r["id"] for r in cleared)
+cleared_balance = sum(
+    l["fields"]["Debit"] - l["fields"]["Credit"]
+    for l in lines
+    if l["fields"]["Transaction"] in cleared_ids
+)
+
+# Create Reconciliation record
+add_records("Reconciliations", [{
+    "Account": 14,
+    "StatementDate": 1739750400,  # date of last bank entry
+    "StatementBalance": 1398.01,
+    "ClearedBalance": cleared_balance,
+    "Difference": 1398.01 - cleared_balance,
+    "Status": "Completed",  # if Difference == 0
+    "StartedAt": 1739923200,  # today
+    "CompletedAt": 1739923200,
+    "Notes": "Reconciled against Schwab export"
+}])
+
+# Verify
+sql_query("SELECT * FROM Transactions WHERE IsBalanced = false")
+```