Reduce restore-time UI load

[wgqqqqq]

Summary

• pass real scene activity through the session/git/shell/terminal views so hidden heavy UI stops acting active
• stagger editor restore probes and add restore-path instrumentation in webview logs
• stop sidebar git consumers from participating in window-focus refresh so background workspaces no longer fan out git status refreshes

Verification

• pnpm run type-check:web
• verified RestoreProbe logs in webview.log and confirmed participatingRepositoryCount drops to 0 on focus restore