MCP: documentation tools, new skills, batch field values

Api: Mcp

Added three documentation tools to the Business NXT MCP: get_table_documentation for plain-English field and workflow prose from doc.visma.net, search_documentation for free-text search over the same source, and get_field_values for enum/bitmask catalogues (with batch decoding via a fields array). New skills cover the supplier invoice approval flow and periodised accounting analysis (income statement, balance sheet, budget vs actual). execute_graphql_query gains a client-side @decodeBase64 directive for base64-wrapped blob fields. init_company now inlines the company’s behaviour-switch bitmasks, and get_skill surfaces an access warning when the signed-in user is missing permissions for the tables a skill needs.