Sequence metadata UI

[AaronPlave]

___REQUIRES_AERIE_PR___="1807"

Corresponding backend branch NASA-AMMOS/plandev#1807. Closes #1767

Summary

• Workspace file metadata UI: Added metadata columns (Last Editor, Last Edited, Created By, Created, Version, Read-Only, User Metadata) to the file browser with a column picker, metadata banner in the editor header with a read-only toggle, and a dedicated right-side metadata panel with a user metadata JSON editor (edit/save/cancel flow)
• Workspace layout refactor: Broke workspace page into separate components - WorkspaceLeftIconRail, WorkspaceRightIconRail, WorkspaceRightPanel, WorkspaceMetadataPanel, FileMetadataBanner, and PanelHeader - with resizable left/right sidebar panels and independent icon rails
• Tooltip wrapper improvements: Switched SidebarMenuButton and sidebar icon rails to use the shared Tooltip.svelte wrapper for consistent behavior, instant tooltips on sidebar buttons and a fix for tooltips reappearing after click
• File browser enhancements: Added "Open Folder" context menu action, column visibility toggle via ActivityTableMenu, compact action cell (menu-only, removed inline delete/open buttons), and metadata-aware sorting
• Editor updates: Added FileMetadataBanner for read-only control and unified the "(Read-only)" label which previously said "Preview Mode" in certain cases.

TODO:

• UI needs to set user metadata with a shallow instead of deep merge option or else user metadata keys will not be deleted when desired. This backend endpoint may not exist yet.

Test plan

•  Verify metadata columns appear in file browser and can be toggled via column picker
•  Verify metadata banner shows in editor with correct last-edited info and read-only checkbox
•  Verify right panel metadata tab shows file metadata fields and user metadata JSON editor (edit/save/cancel)
•  Verify user metadata editor discards changes on file switch or tab change
•  Verify sidebar tooltips appear instantly and switch smoothly between buttons
•  Verify left/right sidebar panels collapse/expand via icon rail buttons and resizable handles
•  Verify "Open Folder" context menu navigates into the folder in the file browser
•  Verify read-only toggle updates file metadata and prevents editing when appropriate