test: add cmd/bd helper coverage and stabilize test runner

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

cmd/bd/reinit_test.go

@@ -9,6 +9,7 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/steveyegge/beads/internal/git"
 	"github.com/steveyegge/beads/internal/storage/sqlite"
 	"github.com/steveyegge/beads/internal/types"
 )
@@ -90,6 +91,7 @@ func testFreshCloneAutoImport(t *testing.T) {
 
 	// Test checkGitForIssues detects issues.jsonl
 	t.Chdir(dir)
+	git.ResetCaches()
 
 	count, path, gitRef := checkGitForIssues()
 	if count != 1 {
@@ -169,6 +171,7 @@ func testDatabaseRemovalScenario(t *testing.T) {
 
 	// Change to test directory
 	t.Chdir(dir)
+	git.ResetCaches()
 
 	// Test checkGitForIssues finds issues.jsonl (canonical name)
 	count, path, gitRef := checkGitForIssues()
@@ -247,6 +250,7 @@ func testLegacyFilenameSupport(t *testing.T) {
 
 	// Change to test directory
 	t.Chdir(dir)
+	git.ResetCaches()
 
 	// Test checkGitForIssues finds issues.jsonl
 	count, path, gitRef := checkGitForIssues()
@@ -323,6 +327,7 @@ func testPrecedenceTest(t *testing.T) {
 
 	// Change to test directory
 	t.Chdir(dir)
+	git.ResetCaches()
 
 	// Test checkGitForIssues prefers issues.jsonl
 	count, path, _ := checkGitForIssues()
@@ -369,6 +374,7 @@ func testInitSafetyCheck(t *testing.T) {
 
 	// Change to test directory
 	t.Chdir(dir)
+	git.ResetCaches()
 
 	// Create empty database (simulating failed import)
 	dbPath := filepath.Join(beadsDir, "test.db")