Frpc-Desktop: baixar versions anteriors

### ✨ New Features

• 🗄️ SQLite persistence：Migrated application data from NeDB to SQLite for more reliable configuration, proxy, and downloaded-version storage.
• 🔄 Automatic data migration：Existing NeDB data is migrated on first launch, validated for integrity, and archived as read-only backup files after a successful upgrade.
• 📄 Proxy pagination：Added pagination to both card and list views, with debounced search for smoother management of large proxy collections.

### 🐛 Bug Fixes

• Fixed tray and window lifecycle issues that could prevent the main window from reopening correctly or leave resources active during shutdown.
• Fixed frpc start, stop, reload, and unexpected-exit handling across supported platforms, including more reliable cleanup of process trees.
• Fixed stale or inconsistent frpc status after restoring an existing process, changing proxy state, or recovering from a disconnected network.
• Fixed connection-error detection when frpc log messages arrive in partial chunks or are written through the log file on macOS.
• Fixed configuration import / export link dialogs overflowing on smaller windows or with long content.
• Fixed duplicate IPC callbacks that could occur after repeatedly navigating between pages.

### ⚡ Performance & Internals

• Improved startup time by moving frpc process discovery and other non-critical work to asynchronous background tasks and delaying update checks until after the first render.
• Reduced page reloads by preserving proxy and configuration views during navigation while refreshing their data when reactivated.
• Reduced renderer bundle overhead through selective Element Plus registration and improved dependency chunking.
• Reduced unnecessary status polling, process recovery attempts, and renderer updates with event-driven log monitoring, status de-duplication, and recovery backoff.
• Improved GitHub release requests with shared response handling, timeouts, size limits, and clearer failure reporting.
• Added SQLite schema migration tracking, foreign-key checks, integrity validation, WAL mode, and graceful database shutdown.
• Updated core runtime dependencies, including Electron 39.8.4, Vue 3.5.31, Element Plus 2.13.6, Pinia 3.0.4, and Vue Router 4.6.4.

### 🔒 Data Safety & Compatibility

• Existing server settings, proxies, downloaded frp versions, startup options, and language preference are preserved during the NeDB-to-SQLite upgrade.
• Database migrations run transactionally and are verified before legacy NeDB files are archived, allowing migration failures to stop safely without silently accepting incomplete data.

### ✨ New Features
• 📥 Download proxy selection：Added selectable download sources for frp packages, including mirrored URLs, improving success rate and speed in restricted or unstable networks.
• 📋 Download page list view：Added card / list view switching so version, size, download count, publish time, and local download status are easier to inspect.
• 🗂️ Proxy page list view：Added list mode to the proxy management page for quicker inspection of proxy name, type, local address, mapped address, remote port, and status.
• 👤 `serverUser` option：Added `serverUser` for `stcp / xtcp / sudp` related scenarios, allowing access to provider proxies created by other server-side users.
• 📦 Support for newer frp imports：Updated bundled frp version metadata and checksum data to support importing newer frp releases.

### 🐛 Bug Fixes
• Fixed overly strict local address validation; `localIP` / `bindAddr` now accept common formats such as `host`, `localhost`, and domain names.
• Fixed abnormal network connectivity check behavior by restoring a real reachable connectivity test URL.
• Fixed unstable recovery behavior after unexpected frpc exits, including repeated checks and inconsistent states.

### ⚡ Performance & Internals
• Improved proxy status toggle interaction, making enable / disable operations more direct.
• Improved mapped-address display and copy workflow, especially in list view.
• Strengthened frpc guardian and recovery logic with cooldown control to avoid repeated aggressive restarts.
• Improved frpc exit logging by recording stdout / stderr for easier troubleshooting.
• Improved disconnect notification behavior to avoid repeated connection-lost prompts within a short time.

### 🌐 Network & Download Improvements
• Updated the GitHub proxy endpoint to improve release metadata fetching and download availability.
• Download link generation now respects the selected mirror source, including copied download URLs.