Add nightly clarity/fuzz build

Author: moodmosaic

.github/workflows/cargo-hack-check.yml

@@ -2,6 +2,12 @@ name: Cargo Hack Check
 
 on:
   workflow_call:
+    inputs:
+      rust-nightly-version:
+        description: Nightly toolchain to use.
+        required: false
+        type: string
+        default: nightly
 
 env:
   RUST_BACKTRACE: full
@@ -116,3 +122,30 @@ jobs:
 
       - name: Run cargo hack check
         run: ${{ matrix.command }}
+
+  fuzz-targets:
+    name: Fuzz targets (nightly)
+    runs-on: ubuntu-latest
+    needs: setup
+    steps:
+      - name: Checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+
+      # Install nightly matching org pattern, pinned to v1.13.0 of the action.
+      - name: Install Rust nightly toolchain
+        id: install_rust
+        uses: actions-rust-lang/setup-rust-toolchain@fb51252c7ba57d633bc668f941da052e410add48 # v1.13.0
+        with:
+          toolchain: ${{ inputs.rust-nightly-version }}
+          cache: true
+          cache-key: >
+            fuzz-${{ hashFiles('clarity/fuzz/Cargo.lock') }}
+
+      - name: Build fuzz targets (compile-only)
+        run: |
+          cargo +${{ inputs.rust-nightly-version }} build \
+            --manifest-path clarity/fuzz/Cargo.toml \
+            --bins \
+            --locked