Update AI/BI dashboard skill with version requirements and field matching rules

[jacksandom]

Summary

• Add version requirements documentation for all widget types
• Document field name matching rule: query.fields.name must exactly match encodings.fieldName to avoid "no selected fields" errors
• Clarify text widget behavior: separate widgets required for title/subtitle (lines array concatenates, not separates)
• Expand filter documentation with global vs page-level distinction and valid widgetType values
• Update complete examples with correct versions, table widgets, and filter patterns
• Add troubleshooting entries for common dashboard errors

Changes

MCP Tool (aibi_dashboards.py):

• Updated create_or_update_dashboard docstring with version requirements table
• Added field name matching guidance in function documentation
• Clarified widget sizing (separate text widgets for title/subtitle)
• Added filter configuration rules (types, versions, queryName binding)

Skill Documentation (SKILL.md):

• Added version requirements table for all widget types
• Rewrote text widget section with correct multilineTextboxSpec usage
• Enhanced counter widget patterns (pre-aggregated vs aggregating)
• Added table widget guidance (version 2, minimal column properties)
• Expanded complete example with bar charts, tables, and filter page
• Added new troubleshooting sections for field mismatch, version, and filter errors