chore: release v0.2.0 and add bump-release workflow

- Bump version to 0.2.0
- Add workflow_dispatch workflow that bumps Cargo.toml, commits, tags,
  and pushes (triggering the existing release workflow)

Author: XciD

.github/workflows/bump-release.yml

@@ -0,0 +1,54 @@
+name: Bump & Release
+
+on:
+  workflow_dispatch:
+    inputs:
+      bump:
+        description: "Version bump type"
+        required: true
+        type: choice
+        options:
+          - patch
+          - minor
+          - major
+
+permissions:
+  contents: write
+
+jobs:
+  bump-and-tag:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Compute new version
+        id: version
+        run: |
+          CURRENT=$(grep -m1 '^version' Cargo.toml | sed 's/.*"\(.*\)"/\1/')
+          IFS='.' read -r MAJOR MINOR PATCH <<< "$CURRENT"
+          case "${{ inputs.bump }}" in
+            major) MAJOR=$((MAJOR + 1)); MINOR=0; PATCH=0 ;;
+            minor) MINOR=$((MINOR + 1)); PATCH=0 ;;
+            patch) PATCH=$((PATCH + 1)) ;;
+          esac
+          NEW="${MAJOR}.${MINOR}.${PATCH}"
+          echo "current=$CURRENT" >> "$GITHUB_OUTPUT"
+          echo "new=$NEW" >> "$GITHUB_OUTPUT"
+          echo "Bumping $CURRENT -> $NEW"
+
+      - name: Bump Cargo.toml
+        run: sed -i "0,/^version = \".*\"/s//version = \"${{ steps.version.outputs.new }}\"/" Cargo.toml
+
+      - name: Update Cargo.lock
+        run: cargo generate-lockfile
+
+      - name: Commit, tag, and push
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add Cargo.toml Cargo.lock
+          git commit -m "chore: release v${{ steps.version.outputs.new }}"
+          git tag "v${{ steps.version.outputs.new }}"
+          git push origin main --tags