Update CI workflow to use actions-rs/toolchain for Rust setup

- Replace actions/setup-rust with actions-rs/toolchain for both stable and nightly toolchain installations.
- Enable minimal profile for faster toolchain setup.
- Clean up comments and ensure consistency in artifact upload steps.

.github/workflows/ci.yml

@@ -21,14 +21,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4 # Updated to v4
+        uses: actions/checkout@v4
 
       - name: Install Rust (stable)
-        uses: actions/setup-rust@v1 # Using the official setup-rust action
+        uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
-          # Optional: enable caching
-          # cache: true
+          override: true
+          profile: minimal # Faster toolchain setup
 
       - name: Install system prerequisites for tests and benchmarks
         run: |
@@ -39,13 +39,6 @@ jobs:
         run: chmod +x ./run_all_tests.sh
 
       - name: Run Comprehensive Test Script
-        # This script should now handle:
-        # - Building and installing Marlin
-        # - Running cargo test --all
-        # - Generating test corpus
-        # - Running bench/dirty-vs-full.sh (produces dirty-vs-full.md)
-        # - (Optional) Running the cold-start benchmark (produces perf.json or similar)
-        # - Running the demo flow tests
         run: ./run_all_tests.sh
 
       - name: Upload Dirty vs Full Benchmark Report
@@ -53,33 +46,33 @@ jobs:
         with:
           name: marlin-dirty-vs-full-benchmark-report
           path: bench/dirty-vs-full.md
-          if-no-files-found: warn # Don't fail if the file isn't there, just warn
+          if-no-files-found: warn
           retention-days: 7
 
-      # If your run_all_tests.sh now also creates perf.json for cold-start
       - name: Upload Cold Start Benchmark JSON (if generated by script)
         uses: actions/upload-artifact@v4
-        if: ${{ success() }} # Only if previous steps succeed
+        if: ${{ success() }}
         with:
           name: marlin-cold-start-perf-json
-          path: perf.json # Assuming run_all_tests.sh now creates this
-          if-no-files-found: ignore # Okay if this specific file isn't generated
+          path: perf.json
+          if-no-files-found: ignore
           retention-days: 7
 
   coverage:
     name: Code Coverage (Tarpaulin)
-    needs: comprehensive-tests # Run after the main tests
+    needs: comprehensive-tests
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
       - name: Install Rust (nightly for Tarpaulin, if needed)
-        uses: actions/setup-rust@v1
+        uses: actions-rs/toolchain@v1
         with:
           toolchain: nightly # Or stable if Tarpaulin works well with it for your project
           override: true
           components: llvm-tools-preview # Component needed by Tarpaulin
+          profile: minimal
 
       - name: Install system prerequisites for Tarpaulin
         run: |
@@ -90,11 +83,10 @@ jobs:
         run: cargo install cargo-tarpaulin
 
       - name: Code Coverage (libmarlin only)
-        # MARLIN_DB_PATH should be unset or point to a temp location for isolated test runs
         run: |
           unset MARLIN_DB_PATH
           cargo +nightly tarpaulin --package libmarlin --out Html --out Xml --fail-under 85
-        continue-on-error: true # So the workflow doesn't fail if coverage is low during development
+        continue-on-error: true
 
       - name: Upload HTML Coverage Report
         uses: actions/upload-artifact@v4