GPT-5.6 Responses-Lite models receive tool_choice "auto" (the forced
hosted choice is invalid under the lite shape, #5771/#5772), so the model
may answer without invoking the hosted web_search tool. The codex search
parser accepted any non-empty answer, returning a stale completion with
zero sources as a successful search.
callCodexSearch now tracks response.web_search_call.* events (and
web_search_call output items) and throws CodexNoWebSearchError when none
occurred. The candidate chain treats that error as retryable, advancing
default lite models to a non-lite model that forces web_search, and
surfaces a clear failure when the model was explicitly configured.
Fixes#6988
(cherry picked from commit a276cd0b3df1d0d041faf0a63fabcbb884e36a91)
- Added optional FetchImpl fields to compaction, proxy, AI, coding-agent, and mnemopi options.
- Threaded injected fetch implementations through OAuth, discovery, and search/LLM request flows.
- Removed exported hookFetch utility and its package entrypoint from utils.
- Replaced global-fetch test monkeypatching with per-test FetchImpl mocks across test suites.
- Centralized OAuth access lifecycle in `AuthStorage`, returning identity metadata and new access-result types.
- Added 60-second skew and strict expiry checks, returning undefined/throws for stale or expired OAuth credentials.
- Removed provider-local token refresh flows from Gemini, Gemini CLI, Antigravity, Kimi, and related OAuth helpers.
- Migrated web-search providers from `AgentStorage` to `AuthStorage` session-aware lookup with `authStorage`/`sessionId`/`signal` flow.
- Replaced `findAnthropicAuth`/DB auth lookup with `buildAnthropicAuthConfig` and explicit base-url override/env fallback ordering.
