fix(llm-access-codex): drop bool literal asserts to satisfy clippy --tests

[acking-you]

Summary

clippy on master is red after PR #4. The failure is clippy::bool_assert_comparison
on three assert_eq!(x, true/false) calls in llm-access-codex/src/request/mod.rs
tests:

error: used `assert_eq!` with a literal bool
   --> llm-access-codex/src/request/mod.rs:345 / :346 / :450

These are pre-existing test asserts carried over verbatim from the original
request.rs. They only surfaced now because CI never ran clippy --tests on
llm-access-codex until the affected-crate CI (PR #5) started linting changed
crates with --tests.

What changed

Three lines, behaviour-identical:

- assert_eq!(prepared.wants_stream, false);          + assert!(!prepared.wants_stream);
- assert_eq!(prepared.force_upstream_stream, true);  + assert!(prepared.force_upstream_stream);
- assert_eq!(prepared.force_upstream_stream, true);  + assert!(prepared.force_upstream_stream);

Verification

• cargo clippy -p llm-access-codex --tests -- -D warnings — clean (this is the
  exact command the affected-crate CI runs for a codex-only change).
• 79 codex + 256 llm-access tests pass.

[gemini-code-assist]

Code Review

This pull request simplifies unit test assertions in llm-access-codex/src/request/mod.rs by replacing assert_eq! comparisons against boolean literals with more idiomatic assert! and assert!(!...) macros. There are no review comments, and the changes are clean and correct. I have no feedback to provide.