ci: enabled workspace crate caching in Rust cache action

- Enabled workspace crate caching in Rust cache action across three CI jobs for faster builds.

.github/workflows/ci.yml

@@ -63,6 +63,7 @@ jobs:
       - uses: Swatinem/rust-cache@v2
         with:
           key: ${{ matrix.target }}
+          cache-workspace-crates: true
       - uses: oven-sh/setup-bun@v2
         with:
           bun-version: "1.3"
@@ -120,6 +121,8 @@ jobs:
         with:
           toolchain: nightly-2026-03-27
       - uses: Swatinem/rust-cache@v2
+        with:
+          cache-workspace-crates: true
       - uses: mlugg/setup-zig@v2
         with:
           version: 0.15.2
@@ -156,6 +159,8 @@ jobs:
         with:
           toolchain: nightly-2026-03-27
       - uses: Swatinem/rust-cache@v2
+        with:
+          cache-workspace-crates: true
       - uses: mlugg/setup-zig@v2
         with:
           version: 0.15.2

rust-toolchain.toml

@@ -1,4 +1,4 @@
 [toolchain]
-channel = "nightly"
+channel = "nightly-2026-03-27"
 components = ["rustfmt", "clippy", "rust-analyzer"]
 targets = ["x86_64-unknown-linux-gnu", "x86_64-pc-windows-msvc"]