GitLab

Antigravity platform serves both Claude and Gemini models, but channel
pricing/mapping is configured under Anthropic/Gemini tabs. The cache
builder was using strict platform equality, causing antigravity groups
to miss all channel pricing entries, resulting in $0 billing.

Add isPlatformPricingMatch() to treat antigravity as superset of
anthropic+gemini for pricing and mapping cache indexing.