fix(retro,ship): count tracked files for the test-file metric, not the working tree

The test-file count ran find over the working tree, sweeping untracked
build output — a Rails repo reported 623 test files when git tracks 17
(37x), skewing retro narratives and ship dashboards. Count via git ls-files
instead; includes the one-line Python-glob widening so non-JS repos stop
undercounting.

Fixes #2307, #1999.

Contributed by @joshRpowell (PR #2308).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

retro/SKILL.md

@@ -1030,7 +1030,7 @@ cat ~/.gstack/greptile-history.md 2>/dev/null || true
 cat TODOS.md 2>/dev/null || true
 
 # 10. Test file count
-find . -name '*.test.*' -o -name '*.spec.*' -o -name '*_test.*' -o -name '*_spec.*' 2>/dev/null | grep -v node_modules | wc -l
+git ls-files 2>/dev/null | grep -E '(\.test\.|\.spec\.|_test\.|_spec\.)' | wc -l
 
 # 11. Regression test commits in window
 git log origin/<default> --since="<window>" --oneline --grep="test(qa):" --grep="test(design):" --grep="test: coverage"

retro/SKILL.md.tmpl

@@ -197,7 +197,7 @@ cat ~/.gstack/greptile-history.md 2>/dev/null || true
 cat TODOS.md 2>/dev/null || true
 
 # 10. Test file count
-find . -name '*.test.*' -o -name '*.spec.*' -o -name '*_test.*' -o -name '*_spec.*' 2>/dev/null | grep -v node_modules | wc -l
+git ls-files 2>/dev/null | grep -E '(\.test\.|\.spec\.|_test\.|_spec\.)' | wc -l
 
 # 11. Regression test commits in window
 git log origin/<default> --since="<window>" --oneline --grep="test(qa):" --grep="test(design):" --grep="test: coverage"