ci(release): fix sccache caching - use SCCACHE_GHA_VERSION instead of non-existent variables

The SCCACHE_GHA_CACHE_TO and SCCACHE_GHA_CACHE_FROM environment variables don't exist in sccache v0.10.0.
They were mentioned in a PR but never implemented. The correct variable is SCCACHE_GHA_VERSION which
creates unique cache namespaces by being SHA256 hashed along with the sccache version string.

This should finally enable proper cache hits across workflow runs.

.github/workflows/release.yml

@@ -124,9 +124,9 @@ jobs:
       - name: Configure sccache cache keys
         shell: bash
         run: |
-          # Use stable cache keys that persist across runs
-          echo "SCCACHE_GHA_CACHE_TO=sccache-${{ matrix.target }}-rust-1.89-v3" >> "$GITHUB_ENV"
-          echo "SCCACHE_GHA_CACHE_FROM=sccache-${{ matrix.target }}-rust-1.89-v3,sccache-${{ matrix.target }}-rust-1.89-v2" >> "$GITHUB_ENV"
+          # SCCACHE_GHA_VERSION creates a unique namespace for the cache
+          # This gets SHA256 hashed to create the cache "name" field
+          echo "SCCACHE_GHA_VERSION=${{ matrix.target }}-rust-1.89-v3" >> "$GITHUB_ENV"
 
       # ✅ Current sccache action (GHAC support). Do not hand-edit ACTIONS_* envs.
       - name: Setup sccache (GHA backend)
@@ -251,7 +251,8 @@ jobs:
           echo "=== Initial sccache stats ==="
           if command -v sccache >/dev/null 2>&1; then
             sccache --show-stats || true
-            echo "Cache keys: TO=${SCCACHE_GHA_CACHE_TO:-not set}, FROM=${SCCACHE_GHA_CACHE_FROM:-not set}"
+            echo "Cache version: ${SCCACHE_GHA_VERSION:-not set}"
+            echo "Expected cache name hash: $(echo -n "sccache-v0.10.0-${SCCACHE_GHA_VERSION}" | shasum -a 256 | cut -d' ' -f1)"
           fi
 
           # Calculate parallel jobs

build-fast.sh

@@ -238,7 +238,8 @@ ${USE_CARGO} build ${USE_LOCKED} --profile "${PROFILE}" --bin code --bin code-tu
 # Check if build succeeded
 if [ $? -eq 0 ]; then
     echo "✅ Build successful!"
-    echo "Binary location: ${BIN_PATH}"
+    echo "Binary location: ./codex-rs/target/${PROFILE}/code"
+    echo ""
     
     # Keep old symlink locations working for compatibility
     # Create symlink in target/release for npm wrapper expectations
@@ -264,8 +265,6 @@ if [ $? -eq 0 ]; then
       ln -sf "../../codex-rs/target/${PROFILE}/code" "$DEST"
     done
     
-    echo "✅ Symlinks updated"
-    echo ""
     # Optional post-link step for deterministic builds: re-link executables
     # with -no_uuid only on macOS. Apply per-bin via `cargo rustc` so
     # dependencies/proc-macro dylibs are not affected.
@@ -297,18 +296,10 @@ if [ $? -eq 0 ]; then
       ln -sf "../${PROFILE}/code" "./target/dev-fast/code"
     fi
 
-    echo "You can run the CLI directly:"
     if [ -n "$BIN_SHA" ]; then
-      echo "  ${ABS_BIN_PATH} (sha256: ${BIN_SHA})"
+      echo "Binary Hash: ${BIN_SHA} ($(du -sh "${ABS_BIN_PATH}" | awk '{print $1}'))"
     else
-      echo "  ${ABS_BIN_PATH}"
-    fi
-    echo "Binary size: $(du -h "${ABS_BIN_PATH}" | cut -f1)"
-    echo ""
-    echo "Build profile: ${PROFILE}"
-    if [ "$PROFILE" = "dev-fast" ]; then
-        echo "  → Optimized for fast iteration (incremental builds enabled)"
-        echo "  → For production build, use: PROFILE=release-prod ./build-fast.sh"
+      echo "Binary Size: $(du -h "${ABS_BIN_PATH}" | cut -f1)"
     fi
     
     if [ "${TRACE_BUILD:-}" = "1" ] && [ -n "$BIN_SHA" ]; then