Fix host-owned notification compatibility and history tabs

[HANCORE-linux]

Summary

• add a narrow adapter over Omarchy's host-owned Notifications service
• support current popupModel and legacy pendingModel/pastModel contracts
• add DND, dismiss, focus, clear, history replay, host replacement, and unavailable handling
• provide explicit Recent/Live tabs with color04 for Recent and color03 for Live
• preserve Clear all and per-notification dismiss actions on both tabs
• add regression coverage and Step 1D validation documentation

Validation

Passed:

• notification adapter regression
• production-boundary regression
• package release, suite, health, and manager tests
• documentation regression
• unpinned status-plugin smoke against the installed host
• AUR scaffold checks
• local live validation with 24 plugins, one Quickshell process, and omarchy-shell shell ping: ok
• real Vesktop notification payloads confirmed in Omarchy host history (app: vesktop)
• independent code review: approved

The pinned host-facing contract gate remains blocked by the documented Omarchy baseline content drift (expected 36dfa90..., installed f365399...). No multi-output, mixed-scale, or full visual-freeze acceptance is claimed from fixtures.

Ownership

Omarchy remains the sole Notifications owner. Shibumi exposes only primitive adapter models and typed actions; it does not create a replacement NotificationServer or read private host state files.