fix: pin inputs (#17471)

## Summary
- Pin Rust git patch dependencies to immutable revisions and make
cargo-deny reject unknown git and registry sources unless explicitly
allowlisted.
- Add checked-in SHA-256 coverage for the current rusty_v8 release
assets, wire those hashes into Bazel, and verify CI override downloads
before use.
- Add rusty_v8 MODULE.bazel update/check tooling plus a Bazel CI guard
so future V8 bumps cannot drift from the checked-in checksum manifest.
- Pin release/lint cargo installs and all external GitHub Actions refs
to immutable inputs.

## Future V8 bump flow
Run these after updating the resolved `v8` crate version and checksum
manifest:

```bash
python3 .github/scripts/rusty_v8_bazel.py update-module-bazel
python3 .github/scripts/rusty_v8_bazel.py check-module-bazel
```

The update command rewrites the matching `rusty_v8_<crate_version>`
`http_file` SHA-256 values in `MODULE.bazel` from
`third_party/v8/rusty_v8_<crate_version>.sha256`. The check command is
also wired into Bazel CI to block drift.

## Notes
- This intentionally excludes RustSec dependency upgrades and
bubblewrap-related changes per request.
- The branch was rebased onto the latest origin/main before opening the
PR.

## Validation
- cargo fetch --locked
- cargo deny check advisories
- cargo deny check
- cargo deny check sources
- python3 .github/scripts/rusty_v8_bazel.py check-module-bazel
- python3 .github/scripts/rusty_v8_bazel.py update-module-bazel
- python3 -m unittest discover -s .github/scripts -p
'test_rusty_v8_bazel.py'
- python3 -m py_compile .github/scripts/rusty_v8_bazel.py
.github/scripts/rusty_v8_module_bazel.py
.github/scripts/test_rusty_v8_bazel.py
- repo-wide GitHub Actions `uses:` audit: all external action refs are
pinned to 40-character SHAs
- yq eval on touched workflows and local actions
- git diff --check
- just bazel-lock-check

## Hash verification
- Confirmed `MODULE.bazel` hashes match
`third_party/v8/rusty_v8_146_4_0.sha256`.
- Confirmed GitHub release asset digests for denoland/rusty_v8
`v146.4.0` and openai/codex `rusty-v8-v146.4.0` match the checked-in
hashes.
- Streamed and SHA-256 hashed all 10 `MODULE.bazel` rusty_v8 asset URLs
locally; every downloaded byte stream matched both `MODULE.bazel` and
the checked-in manifest.

## Pin verification
- Confirmed signing-action pins match the peeled commits for their tag
comments: `sigstore/cosign-installer@v3.7.0`, `azure/login@v2`, and
`azure/trusted-signing-action@v0`.
- Pinned the remaining tag-based action refs in Bazel CI/setup:
`actions/setup-node@v6`, `facebook/install-dotslash@v2`,
`bazelbuild/setup-bazelisk@v3`, and `actions/cache/restore@v5`.
- Normalized all `bazelbuild/setup-bazelisk@v3` refs to the peeled
commit behind the annotated tag.
- Audited Cargo git dependencies: every manifest git dependency uses
`rev` only, every `Cargo.lock` git source has `?rev=<sha>#<same-sha>`,
and `cargo deny check sources` passes with `required-git-spec = "rev"`.
- Shallow-fetched each distinct git dependency repo at its pinned SHA
and verified Git reports each object as a commit.

.github/actions/linux-code-sign/action.yml

@@ -12,7 +12,7 @@ runs:
   using: composite
   steps:
     - name: Install cosign
-      uses: sigstore/cosign-installer@v3.7.0
+      uses: sigstore/cosign-installer@dc72c7d5c4d10cd6bcb8cf6e3fd625a9e5e537da # v3.7.0
 
     - name: Cosign Linux artifacts
       shell: bash

.github/actions/setup-bazel-ci/action.yml

@@ -18,7 +18,7 @@ runs:
   steps:
     - name: Set up Node.js for js_repl tests
       if: inputs.install-test-prereqs == 'true'
-      uses: actions/setup-node@v6
+      uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6
       with:
         node-version-file: codex-rs/node-version.txt
 
@@ -26,7 +26,7 @@ runs:
     # See https://github.com/openai/codex/pull/7617.
     - name: Install DotSlash
       if: inputs.install-test-prereqs == 'true'
-      uses: facebook/install-dotslash@v2
+      uses: facebook/install-dotslash@1e4e7b3e07eaca387acb98f1d4720e0bee8dbb6a # v2
 
     - name: Make DotSlash available in PATH (Unix)
       if: inputs.install-test-prereqs == 'true' && runner.os != 'Windows'
@@ -39,7 +39,7 @@ runs:
       run: Copy-Item (Get-Command dotslash).Source -Destination "$env:LOCALAPPDATA\Microsoft\WindowsApps\dotslash.exe"
 
     - name: Set up Bazel
-      uses: bazelbuild/setup-bazelisk@v3
+      uses: bazelbuild/setup-bazelisk@b39c379c82683a5f25d34f0d062761f62693e0b2 # v3
 
     - name: Configure Bazel repository cache
       id: configure_bazel_repository_cache

.github/actions/setup-rusty-v8-musl/action.yml

@@ -0,0 +1,49 @@
+name: setup-rusty-v8-musl
+description: Download and verify musl rusty_v8 artifacts for Cargo builds.
+inputs:
+  target:
+    description: Rust musl target triple.
+    required: true
+
+runs:
+  using: composite
+  steps:
+    - name: Configure musl rusty_v8 artifact overrides and verify checksums
+      shell: bash
+      env:
+        TARGET: ${{ inputs.target }}
+      run: |
+        set -euo pipefail
+
+        case "${TARGET}" in
+          x86_64-unknown-linux-musl|aarch64-unknown-linux-musl)
+            ;;
+          *)
+            echo "Unsupported musl rusty_v8 target: ${TARGET}" >&2
+            exit 1
+            ;;
+        esac
+
+        version="$(python3 "${GITHUB_WORKSPACE}/.github/scripts/rusty_v8_bazel.py" resolved-v8-crate-version)"
+        release_tag="rusty-v8-v${version}"
+        base_url="https://github.com/openai/codex/releases/download/${release_tag}"
+        binding_dir="${RUNNER_TEMP}/rusty_v8"
+        archive_path="${binding_dir}/librusty_v8_release_${TARGET}.a.gz"
+        binding_path="${binding_dir}/src_binding_release_${TARGET}.rs"
+        checksums_path="${binding_dir}/rusty_v8_release_${TARGET}.sha256"
+        checksums_source="${GITHUB_WORKSPACE}/third_party/v8/rusty_v8_${version//./_}.sha256"
+
+        mkdir -p "${binding_dir}"
+        curl -fsSL "${base_url}/librusty_v8_release_${TARGET}.a.gz" -o "${archive_path}"
+        curl -fsSL "${base_url}/src_binding_release_${TARGET}.rs" -o "${binding_path}"
+        grep -E "  (librusty_v8_release_${TARGET}[.]a[.]gz|src_binding_release_${TARGET}[.]rs)$" \
+          "${checksums_source}" > "${checksums_path}"
+
+        if [[ "$(wc -l < "${checksums_path}")" -ne 2 ]]; then
+          echo "Expected exactly two checksums for ${TARGET} in ${checksums_source}" >&2
+          exit 1
+        fi
+
+        (cd "${binding_dir}" && sha256sum -c "${checksums_path}")
+        echo "RUSTY_V8_ARCHIVE=${archive_path}" >> "${GITHUB_ENV}"
+        echo "RUSTY_V8_SRC_BINDING_PATH=${binding_path}" >> "${GITHUB_ENV}"

.github/actions/windows-code-sign/action.yml

@@ -27,14 +27,14 @@ runs:
   using: composite
   steps:
     - name: Azure login for Trusted Signing (OIDC)
-      uses: azure/login@v2
+      uses: azure/login@a457da9ea143d694b1b9c7c869ebb04ebe844ef5 # v2
       with:
         client-id: ${{ inputs.client-id }}
         tenant-id: ${{ inputs.tenant-id }}
         subscription-id: ${{ inputs.subscription-id }}
 
     - name: Sign Windows binaries with Azure Trusted Signing
-      uses: azure/trusted-signing-action@v0
+      uses: azure/trusted-signing-action@1d365fec12862c4aa68fcac418143d73f0cea293 # v0
       with:
         endpoint: ${{ inputs.endpoint }}
         trusted-signing-account-name: ${{ inputs.account-name }}