Add corex library with resource-aware execution primitives

- Implement CI workflow for formatting, linting, testing, and documentation checks.
- Create publish workflow for automated publishing to crates.io.
- Add .gitignore to exclude build artifacts and editor files.
- Define Cargo.toml for corex and corex-core with dependencies and metadata.
- Add README.md files for corex and corex-core with usage instructions and licensing.
- Implement core execution primitives: spawn_io, compute, and spawn_bg with panic isolation.
- Establish global engine context for resource management based on logical CPU cores.
- Introduce error handling for compute panics.

.github/workflows/publish.yml

@@ -0,0 +1,23 @@
+name: Publish to crates.io
+
+on:
+  push:
+    tags: ["v*.*.*"]
+
+jobs:
+  publish:
+    name: Publish
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - name: Publish corex-core
+        run: cargo publish -p corex-core --allow-dirty --no-verify
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
+      - name: Wait for crates.io indexing
+        run: sleep 30
+      - name: Publish corex
+        run: cargo publish -p corex --allow-dirty --no-verify
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}