feat(ux): enhance usability with high-res page preview, global loading mask, and i18n localization

[gzz727007]

🦭 Pull Request Description

Summary of Changes

This PR brings comprehensive usability, mobile responsiveness, and internationalization (i18n) improvements across the tool suite:

1. Clean State Reset on Navigation:
   • Removed <KeepAlive> wrapper around the router-view in App.vue to ensure switching between tools automatically unmounts previous states and returns to a fresh initial screen.
2. Global Loading Mask with Glassmorphism Design:
   • Created GlobalLoadingMask.vue and useGlobalLoading.js with full i18n localization.
   • Connected it to large document loading operations (e.g. in CompressTool.vue) to block interaction race conditions and prevent target size options from being unexpectedly overridden.
3. High-Resolution Page Preview System:
   • Built a reusable PagePreviewModal.vue component equipped with interactive zoom controls (0.5x ~ 3.0x), fit-to-screen reset, mouse wheel zoom (Ctrl + Wheel), and keyboard shortcuts (+, -, 0, Esc).
   • Integrated on-the-fly 2.5x high-DPI rendering and native page rotation across:
     • OrganizeTool.vue (Visual Page Reorder, Rotate & Delete)
     • SplitTool.vue (Page Split & Extraction, with persistent document lifecycle)
     • PdfToImageTool.vue (PDF to Image conversion)
     • ImageToPdfTool.vue (Image to PDF conversion, with support for scanner-enhanced previews)
4. Card UI Overhaul & Touch/Mobile Responsiveness:
   • Re-architected thumbnail cards in OrganizeTool.vue to separate header actions from thumbnail hover overlays, permanently eliminating button-and-badge crowding and overlapping.
   • Adapted actions with responsive visibility (opacity-85 md:opacity-0 md:group-hover:opacity-100) so mobile/touch users can tap buttons directly without relying on desktop mouse hover.
5. Target Size Compression Progress Internationalization:
   • Replaced hardcoded English progress messages in src/utils/pdfCompress.js with dynamic t() calls.
   • Added complete translations to zh.json, en.json, de.json, es.json, and fr.json.

Type of Change

• 🐛 Bug fix (non-breaking change fixing an issue)
• ✨ New feature (non-breaking change adding functionality)
• ⚡ Performance optimization (rendering, memory, or bundle size)
• 🎨 UI / UX refinement
• 🌍 Internationalization / Translations (new or updated language)
• 📝 Documentation update (README, Guides, Comments)
• 🧪 Test suite enhancement

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🛡️ Privacy & Quality Checklist

• 100% Client-Side Invariant: All code runs strictly in the browser RAM / WebAssembly. No user documents or telemetry data are ever sent over the network.
• Automated Tests: I have verified that all existing tests pass (npm test). (35 test files, 224 unit tests passing).
• New Tests Added: Updated unit test assertion to support localized progress strings in tests/compressTargetSize.test.js.
• Responsive & Cross-Browser: Verified that UI works smoothly across desktop and mobile screens.
• Self-Review: I have performed a self-review of my own code and removed unnecessary console.log statements.

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Related Issues

Closes #

[cloudflare-workers-and-pages]

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Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	pdfseal	f36cd60	Commit Preview URL Branch Preview URL	Sep 24 2026, 02:45 PM