ci: add cargo clippy lint step to chat and stream CI workflows

Add clippy with -D warnings (deny all warnings) to both Rust CI
pipelines. The production-deploy workflow already had clippy.

This ensures lint issues are caught before merge for both services.

Addresses audit finding D15: clippy not present in all Rust workflows.

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/workflows/chat-ci.yml

@@ -23,6 +23,11 @@ jobs:
 
       - name: Set up Rust
         uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+
+      - name: Lint with clippy
+        run: cargo clippy --all-targets -- -D warnings
 
       - name: Run tests
         run: cargo test --all

.github/workflows/stream-ci.yml

@@ -23,6 +23,11 @@ jobs:
 
       - name: Set up Rust
         uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+
+      - name: Lint with clippy
+        run: cargo clippy --all-targets -- -D warnings
 
       - name: Run tests
         run: cargo test --all