feat: overhaul quality checks and expand test suite for clean and optimize features

tests/regression_bugs.bats

@@ -1,6 +1,4 @@
 #!/usr/bin/env bats
-# Regression tests for previously fixed bugs
-# Ensures历史bug不再复现
 
 setup() {
     PROJECT_ROOT="$(cd "${BATS_TEST_DIRNAME}/.." && pwd)"
@@ -9,12 +7,8 @@ setup() {
     mkdir -p "$HOME/.config/mole"
 }
 
-# =================================================================
-# 退出问题回归测试 (bb21bb1, 4b6c436, d75c34d)
-# =================================================================
 
 @test "find with non-existent directory doesn't cause script exit (pipefail bug)" {
-    # 这个模式曾导致 lib/clean/user.sh 在 pipefail 模式下意外退出
     result=$(bash -c '
         set -euo pipefail
         find /non/existent/dir -name "*.cache" 2>/dev/null || true
@@ -24,7 +18,6 @@ setup() {
 }
 
 @test "browser directory check pattern is safe when directories don't exist" {
-    # 修复模式：先检查目录是否存在
     result=$(bash -c '
         set -euo pipefail
         search_dirs=()
@@ -44,7 +37,6 @@ setup() {
         set -euo pipefail
         search_dirs=()
 
-        # 这不应该执行且不应该报错
         if [[ ${#search_dirs[@]} -gt 0 ]]; then
             echo "should not reach here"
         fi
@@ -53,9 +45,6 @@ setup() {
     [[ "$result" == "survived" ]]
 }
 
-# ===============================================================
-# 更新检查回归测试 (260254f, b61b3f7, 2a64cae, 7a9c946)
-# ===============================================================
 
 @test "version comparison works correctly" {
     result=$(bash -c '
@@ -92,7 +81,6 @@ setup() {
 }
 
 @test "network timeout prevents hanging (simulated)" {
-    # curl 超时参数应该生效
     # shellcheck disable=SC2016
     result=$(timeout 5 bash -c '
         result=$(curl -fsSL --connect-timeout 1 --max-time 2 "http://192.0.2.1:12345/test" 2>/dev/null || echo "failed")
@@ -113,9 +101,6 @@ setup() {
     [[ "$result" == "handled" ]]
 }
 
-# ===============================================================
-# Pipefail 模式安全模式测试
-# ===============================================================
 
 @test "grep with no match doesn't cause exit in pipefail mode" {
     result=$(bash -c '
@@ -145,9 +130,6 @@ setup() {
     [[ "$result" == "1" ]]
 }
 
-# ===============================================================
-# 实际场景回归测试
-# ===============================================================
 
 @test "safe_remove pattern doesn't fail on non-existent path" {
     result=$(bash -c "