feat(sheets): add text wrapping, alignment, and font formatting to format_sheet_range

Extends format_sheet_range with new parameters:
- wrap_strategy: WRAP, CLIP, OVERFLOW_CELL
- horizontal_alignment: LEFT, CENTER, RIGHT
- vertical_alignment: TOP, MIDDLE, BOTTOM
- bold: boolean for bold text
- italic: boolean for italic text
- font_size: integer for font size in points

All parameters work alongside existing color and number format options.
Includes 21 unit tests covering all new functionality.
Added to extended tier in tool_tiers.yaml.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

core/tool_tiers.yaml

@@ -85,6 +85,7 @@ sheets:
   extended:
     - list_spreadsheets
     - get_spreadsheet_info
+    - format_sheet_range
   complete:
     - create_sheet
     - read_spreadsheet_comments