ci: cache sccache local disk via actions/cache for hosted runners

.github/workflows/e2e.yml

@@ -45,6 +45,14 @@ jobs:
         with:
           toolchain: "1.92.0"
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+          restore-keys: |
+            sccache-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - uses: Swatinem/rust-cache@v2
@@ -94,6 +102,13 @@ jobs:
           cd tests/pipeline-validation
           PIPELINE_TEST_URL=http://127.0.0.1:4545 cargo test --test validate
 
+      - name: Save sccache cache
+        if: always() && github.ref == 'refs/heads/main'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+
   pipeline-validation-gpu:
     name: Pipeline Validation (GPU)
     # Skip for fork PRs — self-hosted runners must not execute untrusted code.
@@ -238,6 +253,14 @@ jobs:
         with:
           toolchain: "1.92.0"
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+          restore-keys: |
+            sccache-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - uses: Swatinem/rust-cache@v2
@@ -330,3 +353,10 @@ jobs:
           name: playwright-results
           path: e2e/test-results/
           retention-days: 7
+
+      - name: Save sccache cache
+        if: always() && github.ref == 'refs/heads/main'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}

.github/workflows/marketplace-build.yml

@@ -107,6 +107,14 @@ jobs:
         with:
           toolchain: "1.92.0"
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-plugins-${{ runner.os }}-${{ hashFiles('plugins/**/Cargo.lock') }}
+          restore-keys: |
+            sccache-plugins-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - name: Verify official plugins metadata is current
@@ -195,6 +203,13 @@ jobs:
           name: marketplace-registry
           path: dist/registry/**
 
+      - name: Save sccache cache
+        if: always()
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-plugins-${{ runner.os }}-${{ hashFiles('plugins/**/Cargo.lock') }}
+
   publish-registry:
     name: Publish Registry (PR)
     needs: [build-marketplace]

.github/workflows/plugins.yml

@@ -162,6 +162,14 @@ jobs:
           toolchain: "1.92.0"
           components: rustfmt, clippy
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-plugins-${{ runner.os }}-${{ hashFiles('plugins/**/Cargo.lock') }}
+          restore-keys: |
+            sccache-plugins-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - name: Build workspace list for cache
@@ -226,3 +234,10 @@ jobs:
             (cd "plugins/native/${plugin}" && CARGO_TARGET_DIR="${{ github.workspace }}/target/plugins" cargo test)
             echo "::endgroup::"
           done
+
+      - name: Save sccache cache
+        if: always() && github.ref == 'refs/heads/main'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-plugins-${{ runner.os }}-${{ hashFiles('plugins/**/Cargo.lock') }}

.github/workflows/release.yml

@@ -53,6 +53,14 @@ jobs:
         with:
           toolchain: "1.92.0"
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+          restore-keys: |
+            sccache-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - uses: Swatinem/rust-cache@v2
@@ -104,6 +112,13 @@ jobs:
           VERSION="${{ steps.version.outputs.version }}"
           sha256sum streamkit-${VERSION}-linux-x64.tar.gz > streamkit-${VERSION}-linux-x64.tar.gz.sha256
 
+      - name: Save sccache cache
+        if: always()
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+
       - name: Upload artifacts
         uses: actions/upload-artifact@v4
         with:

.github/workflows/skit.yml

@@ -46,6 +46,14 @@ jobs:
           toolchain: "1.92.0"
           components: rustfmt, clippy
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+          restore-keys: |
+            sccache-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - uses: Swatinem/rust-cache@v2
@@ -72,6 +80,13 @@ jobs:
       - name: Check advisories
         run: cargo deny check advisories
 
+      - name: Save sccache cache
+        if: always() && github.ref == 'refs/heads/main'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+
   test:
     name: Test
     runs-on: ubuntu-22.04
@@ -108,6 +123,14 @@ jobs:
         with:
           toolchain: "1.92.0"
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+          restore-keys: |
+            sccache-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - uses: Swatinem/rust-cache@v2
@@ -122,6 +145,13 @@ jobs:
           cargo test --locked -p streamkit-server --features "moq"
           cargo test --locked -p streamkit-server --features "mcp"
 
+      - name: Save sccache cache
+        if: always() && github.ref == 'refs/heads/main'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+
   test-gpu:
     name: Test (GPU)
     # Skip for fork PRs — self-hosted runners must not execute untrusted code.
@@ -208,6 +238,14 @@ jobs:
         with:
           toolchain: "1.92.0"
 
+      - name: Restore sccache cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
+          restore-keys: |
+            sccache-${{ runner.os }}-
+
       - uses: mozilla-actions/sccache-action@v0.0.9
 
       - uses: Swatinem/rust-cache@v2
@@ -221,3 +259,10 @@ jobs:
           cargo build --locked --workspace --release
           cargo build --locked -p streamkit-server --bin skit --release --features "moq"
           cargo build --locked -p streamkit-client --bin skit-cli --release
+
+      - name: Save sccache cache
+        if: always() && github.ref == 'refs/heads/main'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/sccache
+          key: sccache-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}