feat: support space-separated quoted strings as widget arguments

[rohal12]

Summary

• Adjacent quoted string literals can now be passed as separate widget arguments without commas: {choice "Label" "target"} works alongside the existing {choice "Label", "target"} syntax
• Only activates when all arguments are quoted strings and no commas are present — expressions with variables or operators still require commas
• Updated widget docs and macro reference to document both syntaxes

Closes #103

How it works

When splitArgs() finds no top-level commas in the raw argument string, it attempts to parse the input as adjacent quoted string literals ("..." or '...') separated by whitespace. If the entire input is consumed and 2+ strings are found, they're returned as individual arguments. Otherwise, the original single-expression behavior is preserved.

Test plan

• 16 unit tests covering comma splitting (unchanged), space-separated quoted strings, fallback cases, and edge cases
• Full test suite passes (926 tests)
• Type-check passes (tsc --noEmit)

🤖 Generated with Claude Code

[github-actions]

Release preview: merging this PR will publish v0.33.0 (minor bump from v0.32.1)

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	79.37%	2432 / 3064
🔵	Statements	78.4%	2662 / 3395
🔵	Functions	70.96%	435 / 613
🔵	Branches	74.1%	1339 / 1807

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
src/components/macros/WidgetInvocation.tsx	93.54%	93.44%	62.5%	97.5%	38, 54, 145, 147, 191

Generated in workflow #171 for commit 472800e by the Vitest Coverage Report Action