Add custom folder selection for cleaning operations

[Copilot]

Extends folder scanning beyond AppData (Roaming/Local/LocalLow) to support arbitrary user-selected directories.

Implementation

• Scanner: Added scan_custom_folder() function that mirrors scan_appdata() but accepts &Path. Custom folders stored in DB with Custom: prefix to distinguish from AppData types.

• Utils: Introduced CUSTOM_FOLDER_PREFIX constant and updated get_appdata_dir() to handle both AppData types and custom paths via prefix detection.

• UI: Extended folder switcher menu with native dialog picker. Display shows either AppData type or custom path.

• State management: Added custom_folder_path: Option<PathBuf> to ClearTabState. Cleared on AppData selection, populated on custom folder selection.

Example Usage

// Before: Only AppData folders
scanner::scan_appdata(tx, "Roaming");

// After: Custom folders supported
scanner::scan_custom_folder(tx, &PathBuf::from("/any/path"));

// Internal representation
get_appdata_dir("Roaming") // -> Some(PathBuf("C:\Users\...\AppData\Roaming"))
get_appdata_dir("Custom:C:\MyFolder") // -> Some(PathBuf("C:\MyFolder"))

All existing operations (delete, move, open, ignore, batch actions) work transparently with custom folders through the unified get_appdata_dir() interface.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>建议可以选择自定义文件夹</issue_title>
<issue_description>对于需要清理的文件夹，可以自定义文件夹地址
这样就不局限appdata了</issue_description>

Comments on the Issue (you are @copilot in this section)

@TC999 具体说下，等有时间实现 @TC999 具体说下，等有时间实现

• Fixes 建议可以选择自定义文件夹 #67

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[coderabbitai]

Important

Review skipped

Bot user detected.

To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

• 🔍 Trigger a full review

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}