5258c5d6e3
PerplexityProvider.isAvailable() accepted authStorage.hasAuth("openrouter")
as a valid credential, so any user with an OpenRouter key configured (for
LLM access) had every webSearch: auto request silently routed through
OpenRouter's perplexity/sonar-pro endpoint. Since Perplexity sits first in
SEARCH_PROVIDER_ORDER, downstream providers like Gemini were never reached
and users saw unexpected charges on their OpenRouter billing.
Auto-chain admission now requires a direct Perplexity credential
(PERPLEXITY_COOKIES, Perplexity OAuth, or PERPLEXITY_API_KEY).
isExplicitlyAvailable still returns true, so users who want the
OpenRouter-backed perplexity/sonar-pro path can opt in by setting
webSearch: perplexity explicitly — the existing OpenRouter fallback in
getApiConfigs handles that case unchanged.
Fixes #3251