feat(cli): Add batch styling operations support

[arcaputo3]

Current State

The batch command currently only supports `put` and `putf` operations for values and formulas:

[
  {"op": "put", "ref": "A1", "value": "Hello"},
  {"op": "putf", "ref": "B1", "formula": "=A1"}
]

Proposal

Extend batch operations to support styling and other mutations:

[
  {"op": "put", "ref": "A1", "value": "Title"},
  {"op": "style", "ref": "A1:E1", "bold": true, "bg": "navy", "fg": "white"},
  {"op": "merge", "ref": "A1:E1"},
  {"op": "border", "ref": "A1:E10", "style": "thin"},
  {"op": "colwidth", "col": "A", "width": 15},
  {"op": "rowheight", "row": 1, "height": 20}
]

Benefits

• Single-pass workbook creation with full formatting
• Atomic operations (all succeed or none)
• Reduced I/O (one read + one write)
• Better for scripted/automated workflows
• Enables complex template population

Proposed Operations

Operation	Properties	Description
put	ref, value	Set cell value (existing)
putf	ref, formula	Set formula (existing)
style	ref, bold, italic, bg, fg, fontSize, fontName, align, valign, wrap, numFormat	Apply cell style
merge	ref	Merge cell range
unmerge	ref	Unmerge cell range
border	ref, style, color	Apply borders
colwidth	col, width	Set column width
rowheight	row, height	Set row height
hide	row OR col	Hide row/column
comment	ref, text, author	Add cell comment

Implementation Notes

1. Parse batch JSON into sealed trait of operations
2. Execute operations sequentially on sheet
3. Validate all operations before executing (fail-fast)
4. Consider transaction-like semantics

Priority

Medium - significant usability improvement for automation.

Related

• Similar to Excel's macro recording capability
• Would enable "template" workflows

[arcaputo3]

Agent Feedback Context

From xl-cli v0.5.0 testing in Anthropic compute environment:

I ran ~20 separate style commands. Consider adding style operations to batch JSON:

[{"op": "style", "range": "A1:D1", "bold": true, "bg": "#012169"}]

This was identified as one of the top 3 priorities for agent use:

1. Fix ImageMagick delegate detection → fix(cli): Detect broken ImageMagick SVG delegate before attempting rasterization #160 created
2. Add CSV/markdown upsert → CSV done, markdown feat(cli): Add markdown table upsert command #159 created
3. Add batch styling (this issue) → reduces command count significantly

The feedback validates this issue as high-priority for LLM agent workflows.

[arcaputo3]

Closed by #219. Batch now supports 17 operations: put, putf, style, merge, unmerge, colwidth, rowheight, comment, remove-comment, clear, col-hide, col-show, row-hide, row-show, autofit, add-sheet, rename-sheet.