Vault Change Feed 1.2.0

• UI i18n: interface text follows the Obsidian app language (English / 中文)
• Multi-instance standby protection: heartbeat writer lock — a second Obsidian instance on the same synced vault now waits in standby instead of corrupting the feed, and takes over automatically
• Cloud sync detection: one-time notice when Obsidian Sync / iCloud / Dropbox / OneDrive / Google Drive / Syncthing / git sync is detected
• Baseline content budget (default 100 MB): oversized vaults keep hashes only for the largest files — change detection stays precise, diff stats degrade gracefully
• Locale detection now falls back to navigator.language