Reviewer noted that an unconditional ExaProvider.isAvailable steered the auto chain into the public MCP fallback before any later-configured provider could run. Restored the credential-gated isAvailable, then split out isExplicitlyAvailable so resolveProviderChain still routes an explicit Exa selection through MCP without affecting other providers.\n\nRefs #1860
Restored Exa's unauthenticated MCP fallback when neither auth storage nor EXA_API_KEY provides credentials. Preserved API-key search ordering and bounded the MCP request with the web-search hard timeout. Updated provider copy and regression coverage for the no-key path.\n\nFixes #1860
ExaProvider.isAvailable() and searchExa() now consult AuthStorage so Exa credentials configured through the broker/credential store work alongside EXA_API_KEY, matching the other API-key search providers.
Refs #1695
- Passed ANTHROPIC_SEARCH_BASE_URL through to Anthropic web search calls that use authStorage fallback credentials instead of only applying it with ANTHROPIC_SEARCH_API_KEY.
- Added regression coverage asserting fallback Anthropic credentials use the search-specific base URL.
- Updated the environment and web_search docs to reflect the actual credential and base URL resolution order.
Fixes#1694
- Expanded the existing entries in docs/environment-variables.md so the override-semantics ('search-only, isolates from main ANTHROPIC_API_KEY / ANTHROPIC_BASE_URL / FOUNDRY_BASE_URL') are spelled out, and added a usage note for enterprise-gateway split routing.
- Surfaced the search-only env vars (ANTHROPIC_SEARCH_API_KEY / ANTHROPIC_SEARCH_BASE_URL / ANTHROPIC_SEARCH_MODEL) in the Anthropic provider section of docs/tools/web_search.md, where users were already looking.
- Added ANTHROPIC_SEARCH_BASE_URL alongside ANTHROPIC_SEARCH_API_KEY in 'omp --help' so the pair shows up together in the CLI env-var summary.
Fixes#1694
roboomp