fix(grep): return bare integer for -c/--count flag

[CtriXin]

Summary

rtk grep -c <pattern> <file> now outputs just the bare integer count, matching plain grep -c semantics.

Root cause: the -c flag was passed through to rg (which outputs file:count format), but the code split on : expecting file:linenum:content, misinterpreting the output. The full grouped match listing was returned instead of the count.

Fix: detect -c/--count in extra_args, route to dedicated run_count() path that sums all per-file counts from rg -c and prints only the integer.

Fixes: #1452

Test Plan

• cargo test grep_cmd — 11 tests pass
• Manual: rtk grep -c foo /tmp/file returns single integer
• Manual: count=$(rtk grep -c pattern file) captures parseable integer

Notes

• Existing grep output (without -c) unchanged
• rg is used when available, grep as fallback (unchanged)

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[pszymkowiak]

[w] wshm · Automated triage by AI

📊 Automated PR Analysis

🐛 Type	bug-fix
🟢 Risk	low

Summary

Fixes the rtk grep -c flag to output a bare integer count instead of misinterpreting ripgrep's file:count format. A dedicated run_count() code path detects the -c/--count flag, sums per-file counts from rg -c output, and prints only the total integer, matching standard grep -c semantics.

Review Checklist

• Tests present
• Breaking change
• Docs updated

Linked issues: #1452

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Analyzed automatically by wshm · This is an automated analysis, not a human review.