fix(tests): make runner worktree exclusions relative to the search root

Both runners excluded */.claude/worktrees/* by absolute path, which
filtered out every test when the repo itself is a Claude worktree.
Search from inside the root so only nested worktrees are skipped.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test-run-tests.sh

@@ -45,8 +45,8 @@ trap cleanup EXIT
 # substitution's subshell and be lost. Registration is the caller's job. Same
 # convention as tests/test-run-bats.sh.
 make_fake_repo() {
-  local dir
-  dir="$(mktemp -d)"
+  local dir="${1:-}"
+  [[ -n "$dir" ]] || dir="$(mktemp -d)"
   mkdir -p "$dir/tests" "$dir/scripts/lib" "$dir/cases"
   cp "$REPO_ROOT/scripts/lib/batch-run.sh" "$dir/scripts/lib/batch-run.sh"
   cp "$RUN_TESTS" "$dir/tests/run-tests.sh"
@@ -670,6 +670,39 @@ else
   pass "--strict and RUN_TESTS_STRICT=1 both dispatch children with RUN_TESTS_STRICT absent"
 fi
 
+# --- A search root that itself sits under .claude/worktrees/ still runs. The
+# worktree exclusion used to match the absolute path, so every suite in a Claude
+# worktree (<repo>/.claude/worktrees/<name>/) was filtered out. It is now
+# relative to the search root, so a worktree nested BELOW the root is still
+# skipped.
+echo ""
+echo "--- a root under .claude/worktrees/ discovers its own suites and still skips nested worktrees ---"
+WT_PARENT="$(mktemp -d)"
+FIXTURES+=("$WT_PARENT")
+WT_DIR="$WT_PARENT/repo/.claude/worktrees/agent-x"
+make_fake_repo "$WT_DIR" >/dev/null
+install_healthy_bats_runner "$WT_DIR"
+add_case "$WT_DIR" test-own.sh <<'EOF'
+#!/usr/bin/env bash
+echo "own suite ran"
+EOF
+mkdir -p "$WT_DIR/cases/.claude/worktrees/nested"
+cat > "$WT_DIR/cases/.claude/worktrees/nested/test-nested.sh" <<'EOF'
+#!/usr/bin/env bash
+echo "nested suite ran"
+exit 1
+EOF
+run_fake "$WT_DIR"
+if [[ $FAKE_RC -ne 0 ]]; then
+  fail "a root under .claude/worktrees/ failed: $FAKE_OUT"
+elif ! grep -q "own suite ran" <<< "$FAKE_OUT"; then
+  fail "a root under .claude/worktrees/ did not run its own suite: $FAKE_OUT"
+elif grep -q "nested suite ran" <<< "$FAKE_OUT"; then
+  fail "a worktree nested below the root was discovered and run: $FAKE_OUT"
+else
+  pass "a root under .claude/worktrees/ runs its own suites and skips nested worktrees"
+fi
+
 echo ""
 echo "Results: $PASS passed, $FAIL failed"
 [[ $FAIL -eq 0 ]]