feat(release): add semantic-release auto versioning

- Add .releaserc.json: conventional commits -> semantic version bump
  (major/minor/patch), updates Cargo.toml + Cargo.lock version, writes
  CHANGELOG.md, commits as 'chore(release): X.Y.Z [skip ci]'
- Add release.yml: runs semantic-release on main push, then triggers
  publish.yml via workflow_dispatch with the new tag
- Update publish.yml: add workflow_dispatch input (tag) so release
  workflow can trigger publish directly (GITHUB_TOKEN tag pushes do not
  trigger 'on: push: tags'); still supports manual tag pushes

.github/workflows/publish.yml

@@ -3,6 +3,15 @@ name: Publish to crates.io
 on:
   push:
     tags: ["v*.*.*"]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Git tag to publish (e.g. v0.2.0). Defaults to latest tag."
+        required: false
+        type: string
+
+permissions:
+  contents: read
 
 jobs:
   publish:
@@ -10,7 +19,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.tag || github.event.ref || github.ref }}
+          fetch-depth: 0
+
       - uses: dtolnay/rust-toolchain@stable
+
       - name: Publish mytheclipse
         run: cargo publish --allow-dirty --no-verify
         env: