Adopt Semifold CI and prepare 0.2.0-alpha pre-release (#62)

Refer: http://semifold.noctisynth.org/

## Summary by Sourcery

Adopt Semifold-based release management and prepare the project for a
0.2.0-alpha pre-release across Rust and UI packages.

New Features:
- Introduce Semifold CI release workflow to orchestrate builds,
publishing, and changelog management.
- Add Semifold status workflow to report release status on pull
requests.
- Add workspace-level Node tooling and scripts to manage Tauri version
bumping and project preparation.

Enhancements:
- Refactor GitHub Actions workflows for build, test, check, and lint to
simplify pnpm usage, update action versions, and standardize artifact
paths.
- Move Rust profile configuration into a new Cargo workspace and add a
pnpm workspace for the UI package.
- Configure Semifold changelog and release metadata for Rust and Node
packages, including alpha pre-release tagging.

Build:
- Replace the tag-triggered GitHub release workflow with a branch-based
Semifold CI pipeline that builds artifacts for Linux, macOS, and Windows
and uploads them for publishing.
- Update CI action versions (checkout, setup-node, upload-artifact,
download-artifact) and adjust Rust cache configuration and artifact
locations.
- Add root workspace package.json, pnpm-workspace.yaml, and pnpm
overrides to centralize tooling and dependency management.

CI:
- Add a dedicated Semifold status GitHub Actions workflow for pull
requests to main.
- Update existing check, lint, test, and build workflows to align with
the new workspace layout and artifact directories.

Deployment:
- Integrate Semifold configuration for automated publishing to crates.io
and npm, including pre-checks, post-version hooks, and use of stored
build artifacts in releases.

Tests:
- Adjust test workflow artifact paths to match the new target directory
structure and workspace configuration.

Chores:
- Remove unused Python packaging files and old Node lockfiles that are
no longer part of the build or release process.

1 files changed, 55 insertions, 0 deletions

diff --git a/.changes/config.toml b/.changes/config.toml
new file mode 100644
index 0000000..c7766ea
--- /dev/null
+++ b/.changes/config.toml
@@ -0,0 +1,55 @@
+[branches]
+base = "main"
+release = "release"
+
+[tags]
+chore = "Chores"
+feat = "New Features"
+fix = "Bug Fixes"
+perf = "Performance Improvements"
+refactor = "Refactors"
+
+[packages."@dropout/ui"]
+path = "ui"
+resolver = "nodejs"
+version-mode = { pre-release.tag = "alpha" }
+
+[packages.dropout]
+path = "src-tauri"
+resolver = "rust"
+version-mode = { pre-release.tag = "alpha" }
+assets = ["artifacts/**/*"]
+
+[resolver.rust.pre-check]
+url = "https://crates.io/api/v1/crates/{{ package.name }}/{{ package.version }}"
+
+[resolver.rust.pre-check.extra-headers]
+User-Agent = "Semifold 0.2.10"
+
+[[resolver.rust.publish]]
+command = "cargo"
+args = ["publish"]
+
+[[resolver.rust.post-version]]
+command = "cargo"
+args = [
+    "generate-lockfile",
+    "--offline",
+]
+dry_run = true
+
+[[resolver.rust.post-version]]
+command = "pnpm"
+args = ["bump-tauri"]
+
+[resolver.nodejs.pre-check]
+url = "https://registry.npmjs.org/{{ package.name }}/{{ package.version }}"
+
+[[resolver.nodejs.publish]]
+command = "npm"
+args = [
+    "publish",
+    "--provenance",
+    "--access",
+    "public",
+]