feat: stabilize category rule operations

approve dcy-001 and add REQ/BAT evidence

pass selected DB path through Streamlit rule actions

expose delete_category_rule MCP tool

add category rule deletion regression

jarca_ledger_mcp/server.py

@@ -154,6 +154,11 @@ def update_category_rule(rule_id: str, match_field: str, pattern: str, category:
     """Update an existing ledger transaction categorization rule."""
     return service.update_category_rule(rule_id, match_field, pattern, category, subcategory, transaction_type, match_type, priority, person, is_fixed, confidence, memo, amount_min, amount_max, day_of_month, active)
 
+@mcp.tool()
+def delete_category_rule(rule_id: str) -> dict:
+    """Delete a transaction categorization rule."""
+    return service.delete_category_rule(rule_id)
+
 @mcp.tool()
 def preview_categorization(limit: int = 1000, only_uncategorized: bool = True) -> dict:
     """Preview category-rule matches before writing categories to transactions."""