[codex] Publish release symbol artifacts (#25649)

## Why

Production Codex binaries are stripped for distribution, which leaves
crashes and samples from released builds without the symbols needed for
useful stack traces. Publish symbols as separate release assets so
production artifacts stay small while released builds remain
symbolicateable.

## What changed

- Add `.github/scripts/archive-release-symbols-and-strip-binaries.sh` to
package platform-native symbols into `codex-symbols-<artifact>.tar.gz`
assets while stripping the corresponding Unix binaries before signing.
- Build release binaries with full debug information before producing
distribution artifacts.
- Publish macOS `.dSYM` bundles, Linux `.debug` files with
`.gnu_debuglink`, and Windows `.pdb` files.
- Strip Linux `bwrap` before computing its packaged-resource digest, but
intentionally omit `bwrap` from symbol archives.
- Preserve symbols artifacts in the unsigned macOS promotion flow.

## Verification

- Ran `shellcheck` and `bash -n` on
`.github/scripts/archive-release-symbols-and-strip-binaries.sh`.
- Parsed the modified workflow YAML files and ran `git diff --check`.
- Built a macOS release smoke binary and verified that the archived
`.dSYM` contains DWARF application source information and has the same
UUID as the stripped production binary.
- Built Linux smoke binaries and verified that the symbol archive
contains `codex.debug`, excludes `bwrap.debug`, leaves the expected
`.gnu_debuglink` in `codex`, and does not mutate the separately stripped
`bwrap` digest.
- Staged a Windows smoke archive and verified that it contains the
expected `.pdb` file.

.github/scripts/archive-release-symbols-and-strip-binaries.sh

@@ -0,0 +1,119 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  cat <<'EOF'
+Usage: archive-release-symbols-and-strip-binaries.sh \
+  --target <rust-target> \
+  --artifact-name <artifact-name> \
+  --release-dir <dir> \
+  --archive-dir <dir> \
+  --binaries "<space-delimited binary basenames>"
+EOF
+}
+
+target=""
+artifact_name=""
+release_dir=""
+archive_dir=""
+binaries=""
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --target)
+      target="${2:?--target requires a value}"
+      shift 2
+      ;;
+    --artifact-name)
+      artifact_name="${2:?--artifact-name requires a value}"
+      shift 2
+      ;;
+    --release-dir)
+      release_dir="${2:?--release-dir requires a value}"
+      shift 2
+      ;;
+    --archive-dir)
+      archive_dir="${2:?--archive-dir requires a value}"
+      shift 2
+      ;;
+    --binaries)
+      binaries="${2:?--binaries requires a value}"
+      shift 2
+      ;;
+    -h|--help)
+      usage
+      exit 0
+      ;;
+    *)
+      echo "Unexpected argument: $1" >&2
+      usage >&2
+      exit 1
+      ;;
+  esac
+done
+
+if [[ -z "$target" || -z "$artifact_name" || -z "$release_dir" || -z "$archive_dir" || -z "$binaries" ]]; then
+  usage >&2
+  exit 1
+fi
+
+symbols_root="${RUNNER_TEMP:-/tmp}/codex-symbols-${artifact_name}"
+symbols_dir="${symbols_root}/codex-symbols-${artifact_name}"
+archive_path="${archive_dir%/}/codex-symbols-${artifact_name}.tar.gz"
+rm -rf "$symbols_root"
+mkdir -p "$symbols_dir" "$archive_dir"
+read -r -a binary_names <<< "$binaries"
+
+case "$target" in
+  *apple-darwin)
+    for binary in "${binary_names[@]}"; do
+      binary_path="${release_dir%/}/${binary}"
+      dsym_path="${binary_path}.dSYM"
+      if [[ ! -f "$binary_path" ]]; then
+        echo "Binary $binary_path not found" >&2
+        exit 1
+      fi
+      if [[ ! -d "$dsym_path" ]]; then
+        echo "dSYM $dsym_path not found" >&2
+        exit 1
+      fi
+
+      cp -RL "$dsym_path" "${symbols_dir}/${binary}.dSYM"
+      strip -S -x "$binary_path"
+    done
+    ;;
+  *linux*)
+    objcopy_bin="${OBJCOPY:-objcopy}"
+    strip_bin="${STRIP:-strip}"
+    for binary in "${binary_names[@]}"; do
+      binary_path="${release_dir%/}/${binary}"
+      debug_path="${symbols_dir}/${binary}.debug"
+      if [[ ! -f "$binary_path" ]]; then
+        echo "Binary $binary_path not found" >&2
+        exit 1
+      fi
+
+      "$objcopy_bin" --only-keep-debug "$binary_path" "$debug_path"
+      "$strip_bin" --strip-debug --strip-unneeded "$binary_path"
+      "$objcopy_bin" --add-gnu-debuglink="$debug_path" "$binary_path"
+    done
+    ;;
+  *windows*)
+    for binary in "${binary_names[@]}"; do
+      pdb_path="${release_dir%/}/${binary}.pdb"
+      if [[ ! -f "$pdb_path" ]]; then
+        echo "PDB $pdb_path not found" >&2
+        exit 1
+      fi
+
+      cp "$pdb_path" "${symbols_dir}/${binary}.pdb"
+    done
+    ;;
+  *)
+    echo "No symbols packaging support for target: $target" >&2
+    exit 1
+    ;;
+esac
+
+rm -f "$archive_path"
+tar -C "$symbols_root" -czf "$archive_path" "codex-symbols-${artifact_name}"