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>

scripts/resolvers/testing.ts

@@ -222,7 +222,7 @@ ls -d test/ tests/ spec/ __tests__/ cypress/ e2e/ 2>/dev/null
 
 \`\`\`bash
 # Count test files before any generation
-find . -name '*.test.*' -o -name '*.spec.*' -o -name '*_test.*' -o -name '*_spec.*' | grep -v node_modules | wc -l
+git ls-files 2>/dev/null | grep -E '(\\.test\\.|\\.spec\\.|_test\\.|_spec\\.)' | wc -l
 \`\`\`
 
 Store this number for the PR body.`);
@@ -430,7 +430,7 @@ If no test framework AND user declined bootstrap → diagram only, no generation
 
 \`\`\`bash
 # Count test files after generation
-find . -name '*.test.*' -o -name '*.spec.*' -o -name '*_test.*' -o -name '*_spec.*' | grep -v node_modules | wc -l
+git ls-files 2>/dev/null | grep -E '(\\.test\\.|\\.spec\\.|_test\\.|_spec\\.)' | wc -l
 \`\`\`
 
 For PR body: \`Tests: {before} → {after} (+{delta} new)\`