Use observation deliveries for ReviewMonitor native rendering

[lynnswap]

Purpose

Align ReviewMonitor owner-bound rendering tests with ObservationBridge v0.10.0 by synchronizing against production ObservationDelivery callbacks and sampled native UI state.

Changes

• Update ObservationBridge to v0.10.0 and keep package pins aligned for the package and ReviewMonitor app project.
• Move rendered/presentation-only content state out of ReviewMonitorUIState and keep child controller presentation state private to the owning controller.
• Retain ObservationDelivery handles in ReviewMonitor view controllers so tests can wait for delivered native rendering instead of render counters or queue flushing.
• Replace manual render timing helpers with ObservationDelivery.values { ... } samples of rendered AppKit state.
• Refresh the log find snapshot when the active find query changes after streaming updates, preserving live find behavior without searching stale snapshots.

Testing

• swift test --build-system swiftbuild --no-parallel
• xcodebuild test -project Tools/ReviewMonitor/CodexReviewMonitor.xcodeproj -scheme CodexReviewMonitor -destination 'platform=macOS,arch=arm64' CODE_SIGNING_ALLOWED=NO CODE_SIGNING_REQUIRED=NO
• git diff --check
• codex-review against main: no findings