[codex] Increase AdMob revenue surfaces

[jdlugo]

What changed

This PR ports the AdMob revenue work onto the current main branch and Cronica.xcodeproj project structure:

• adds AdMob package integration plus app ID / ATT usage keys
• starts Mobile Ads at launch, preloads launch-visible inventory, and presents app-open ads on foreground return
• adds shared interstitial, rewarded, and app-open coordination with lifecycle telemetry
• uses production native/interstitial/rewarded/app-open ad unit IDs
• adds native ad surfaces on Home, Search results, Settings, overview/detail, and iPad detail layouts
• presents interstitials before high-intent outbound trailer/provider actions
• gates ads for Tip Jar purchasers and preview-video monetization-disabled runs
• adds focused AdMob configuration, gating, startup, and coordinator tests
• includes the AdMob history CSV and weekly revenue report used for the revenue work

Publishing note

The previous PR branch was based on an older local branch that had drifted from upstream and carried large screenshot asset history. This update replaces it with a single clean commit on top of current main, avoiding those oversized assets and resolving the GitHub merge conflict.

Validation

• xcodebuild test -project Cronica.xcodeproj -scheme "Cronica (EN-US)" -destination 'platform=iOS Simulator,name=iPhone 17,OS=26.2' -only-testing:"Cronica Tests/AdCoordinatorTests" -only-testing:"Cronica Tests/AdStartupCoordinatorTests" -only-testing:"Cronica Tests/AdConfigurationTests" -only-testing:"Cronica Tests/AdGatingTests"
• git diff --check HEAD~1..HEAD