fix(grep): keep the glob attached to --include so MSYS cannot expand it

[dchaudhari7177]

Problem

grep passed the filter as two arguments:

cmd = [grep_bin, *flags, "--include", glob, "-e", pattern, path]

On Windows the grep found on PATH is normally Git for Windows' MSYS build, and its runtime glob-expands a bare * argument against the current directory before grep parses it. The filter then names whatever file sorted first in the cwd, so a search of any other directory silently reports No matches.

This isn't an edge case — with Git installed, shutil.which("grep") finds it, so every grep call takes this path. The tool returns "no matches" for everything.

It's also why tests/test_tools.py::test_grep and ::test_grep_ignore_case fail on a Windows checkout of main:

assert 'needle in hay' in "No matches for 'needle' in C:\...\test_grep0."

Reproduction

cwd holding one unrelated file, searching a temp tree containing two matches:

--include *        rc=1  matches=0     <- expansion hits the cwd, not the target
--include=*        rc=0  matches=2
MSYS=noglob + sep  rc=0  matches=2
omitted            rc=0  matches=2

Fix

One character — attach the glob to the flag, --include=<glob>. MSYS doesn't expand a token containing =, and the two spellings are equivalent to GNU grep everywhere else.

I preferred this to the alternatives: omitting --include when glob == "*" fixes only the default and leaves *.py mangled, and setting MSYS=noglob in the environment is a bigger hammer that affects the whole child process.

Filtering is unaffected:

--include=*        -> ['a.txt', 'b.py', 'c.md']
--include=*.py     -> ['b.py']
--include=*.txt    -> ['a.txt']

Tests

The two existing greps now pass. Three added:

• test_grep_passes_include_as_one_argument and test_grep_include_defaults_to_everything assert the command shape, not the result. This is deliberate: without the MSYS runtime both spellings behave identically, so on a Linux runner a revert to the two-argument form would otherwise stay green.
• test_grep_filters_by_glob checks end-to-end that a glob still selects files.

Against main (stashing only gcode/tools.py): 5 failed, 17 passed. With the fix, the full suite is 57 passed — up from 52 passed / 2 failed. ruff check clean.

Found while looking at #63 (differential tests, _grep_python vs system grep) — that issue is a good idea independently, since this class of divergence is exactly what it would catch. Happy to send it separately.