feat(issue-139): push files to object

[Prem759-0]

Resolves #139

This PR implements the functionality to push workspace files to a Second Life object in the Object Explorer, mirroring the existing Pull logic.

Changes included:

• Target Tracking: Monitors the slVscodeEdit:objectSelected context key and tracks the focused object/prim in the Object Explorer via the focusChanged message.
• Push Command (slVscodeEdit.pushFilesToObject): Registered and added to the context menu in the workspace explorer when connected.
• Pre-flight & Validation:
  • Automatically expands directory selections (one level deep) and ignores nested directories.
  • Skips non-text/binary files automatically.
  • Truncates filenames to a maximum of 63 characters (SL limit).
  • Performs collision checks to prevent mapping multiple files to the same inventory item.
• Serialization & Execution:
  • Prompts to save all unsaved editors before proceeding.
  • Provides a detailed confirmation dialog summarizing creates, updates, and any potential warnings (e.g., >64KB limit).
  • Updates existing items using saveObjectContent and creates new items using createObjectItem.
• Live Sync Auto-linking: Automatically links pushed files to the object using moveVirtualFile, enabling real-time bidirectional syncing instantly after a successful push.