Fix CI issues: proper toolchain setup and conditional integration tests

Co-authored-by: oleander <220827+oleander@users.noreply.github.com>

Author: Copilot

.github/workflows/ci.yml

@@ -47,21 +47,29 @@ jobs:
         with:
           cache-on-failure: true
 
-      - name: Set up Rust
-        uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ matrix.rust }}
+      - name: Set up Rust (nightly)
+        if: matrix.rust == 'nightly'
+        uses: dtolnay/rust-toolchain@nightly
+        
+      - name: Set up Rust (stable)
+        if: matrix.rust == 'stable'
+        uses: dtolnay/rust-toolchain@stable
 
       - name: Install fish (Linux)
         if: startsWith(matrix.os, 'ubuntu')
-        run: sudo apt install fish
+        run: sudo apt update && sudo apt install -y fish
 
       - name: Install fish (macOS)
         if: startsWith(matrix.os, 'macos')
         run: brew install fish
 
       - name: Run integration tests
+        if: env.OPENAI_API_KEY != ''
         run: fish ./scripts/integration-tests
+        
+      - name: Skip integration tests (no API key)
+        if: env.OPENAI_API_KEY == ''
+        run: echo "Skipping integration tests - no OPENAI_API_KEY configured"
 
       - name: Run cargo test
         run: cargo test