bazel: lint rust_test targets in clippy workflow (#16450)

## Why

`cargo clippy --tests` was catching warnings in inline `#[cfg(test)]`
code that the Bazel PR Clippy lane missed. The existing Bazel invocation
linted `//codex-rs/...`, but that did not apply Clippy to the generated
manual `rust_test` binaries, so warnings in targets such as
`//codex-rs/state:state-unit-tests-bin` only surfaced as plain compile
warnings instead of failing the lint job.

## What Changed

- added `scripts/list-bazel-clippy-targets.sh` to expand the Bazel
Clippy target set with the generated manual `rust_test` rules while
still excluding `//codex-rs/v8-poc:all`
- updated `.github/workflows/bazel.yml` to use that expanded target list
in the Bazel Clippy PR job
- updated `just bazel-clippy` to use the same target expansion locally
- updated `.github/workflows/README.md` to document that the Bazel PR
lint lane now covers inline `#[cfg(test)]` code

## Verification

- `./scripts/list-bazel-clippy-targets.sh` includes
`//codex-rs/state:state-unit-tests-bin`
- `bazel build --config=clippy -- //codex-rs/state:state-unit-tests-bin`
now fails with the same unused import in `state/src/runtime/logs.rs`
that `cargo clippy --tests` reports

.github/workflows/bazel.yml

@@ -154,13 +154,17 @@ jobs:
           mkdir -p "${RUNNER_TEMP}/bazel-execution-logs"
           echo "CODEX_BAZEL_EXECUTION_LOG_COMPACT_DIR=${RUNNER_TEMP}/bazel-execution-logs" >> "${GITHUB_ENV}"
 
-      - name: bazel build --config=clippy //codex-rs/...
+      - name: bazel build --config=clippy lint targets
         env:
           BUILDBUDDY_API_KEY: ${{ secrets.BUILDBUDDY_API_KEY }}
         shell: bash
         run: |
-          # Keep the initial Bazel clippy scope on codex-rs and out of the
-          # V8 proof-of-concept target for now.
+          bazel_target_lines="$(./scripts/list-bazel-clippy-targets.sh)"
+          bazel_targets=()
+          while IFS= read -r target; do
+            bazel_targets+=("${target}")
+          done <<< "${bazel_target_lines}"
+
           ./.github/scripts/run-bazel-ci.sh \
             -- \
             build \
@@ -168,8 +172,7 @@ jobs:
             --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
             --build_metadata=TAG_job=clippy \
             -- \
-            //codex-rs/... \
-            -//codex-rs/v8-poc:all
+            "${bazel_targets[@]}"
 
       - name: Upload Bazel execution logs
         if: always() && !cancelled()