feat: Add Media Assets sidebar tab for file management

- Implement new sidebar tab for managing imported/generated files
- Add separate composables for internal and cloud environments
- Display execution time from history API on generated outputs
- Support gallery view with keyboard navigation
- Auto-truncate long filenames in cloud environment
- Add utility functions for media type detection
- Enable feature only in development mode

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/locales/en/main.json

@@ -595,6 +595,8 @@
     "nodeLibrary": "Node Library",
     "workflows": "Workflows",
     "templates": "Templates",
+    "assets": "Assets",
+    "mediaAssets": "Media Assets",
     "labels": {
       "queue": "Queue",
       "nodes": "Nodes",
@@ -602,8 +604,15 @@
       "workflows": "Workflows",
       "templates": "Templates",
       "console": "Console",
-      "menu": "Menu"
+      "menu": "Menu",
+      "assets": "Assets",
+      "imported": "Imported",
+      "generated": "Generated"
     },
+    "noFilesFound": "No files found",
+    "noImportedFiles": "No imported files found",
+    "noGeneratedFiles": "No generated files found",
+    "noFilesFoundMessage": "Upload files or generate content to see them here",
     "browseTemplates": "Browse example templates",
     "openWorkflow": "Open workflow in local file system",
     "newBlankWorkflow": "Create a new blank workflow",