BOT: Fix #807: Clean up linter statements around cli conditions

[nikosbosse]

Summary

• Replaces all double-quoted cli condition names ("!" =, "i" =, "x" =, "v" =) with backtick-quoted equivalents (`!` =, `i` =, etc.) across 17 R source files (53 occurrences)
• Removes all keyword_quote_linter nolint annotations (~28 blocks), keeping other linter suppressions (object_usage_linter, duplicate_argument_linter) where still needed
• Enables keyword_quote_linter by removing its NULL exclusion from .lintr
• Adds regression tests to prevent reintroduction of double-quoted cli condition names

Root cause

The keyword_quote_linter was disabled in .lintr and suppressed with #nolint blocks because cli condition names like "!" = were flagged as unnecessary quotes. The fix is to use backtick-quoted names (`!` =), which are semantically identical to cli but satisfy the linter.

Test plan

• New tests verify no double-quoted cli condition names remain
• New tests verify no keyword_quote_linter nolint annotations remain
• New tests verify keyword_quote_linter is not disabled in .lintr
• Regression guard confirms cli messages render correctly
• Full test suite passes (683 tests, 0 failures)
• R CMD check: 0 errors, 0 warnings, 2 notes (pre-existing)

Fixes #807

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 98.11321% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 97.83%. Comparing base (ac0c01a) to head (22b9435).

Files with missing lines	Patch %	Lines
R/get-pit-histogram.R	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1086   +/-   ##
=======================================
  Coverage   97.83%   97.83%           
=======================================
  Files          35       35           
  Lines        1845     1845           
=======================================
  Hits         1805     1805           
  Misses         40       40           

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[nikosbosse]

CLAUDE: Approved. Clean, mechanical fix that correctly replaces all 53 double-quoted cli condition names with backtick-quoted equivalents across 17 R source files, removes/simplifies all associated nolint blocks, re-enables keyword_quote_linter in .lintr, and adds 5 well-designed regression tests. All nolint start/end blocks are properly balanced, no remaining double-quoted patterns, and combo blocks correctly simplified to retain only still-needed linters. No issues found.