ci(release): add semantic-release for automated versioning

Configures semantic-release to run on every push to main, creating
GitHub Releases and version tags from conventional commits. Docker
workflow already triggers on v*.*.* tags so builds follow automatically.

Author: Xe

.github/workflows/release.yml

@@ -0,0 +1,30 @@
+name: Release
+
+on:
+  push:
+    branches: ["main"]
+
+permissions:
+  contents: write
+  issues: write
+  pull-requests: write
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+        with:
+          node-version: latest
+
+      - run: npm ci
+
+      - name: Run semantic-release
+        run: npx semantic-release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.releaserc.json

@@ -0,0 +1,16 @@
+{
+  "branches": ["main"],
+  "plugins": [
+    "@semantic-release/commit-analyzer",
+    "@semantic-release/release-notes-generator",
+    ["@semantic-release/npm", { "npmPublish": false }],
+    [
+      "@semantic-release/git",
+      {
+        "assets": ["package.json", "package-lock.json"],
+        "message": "chore(release): ${nextRelease.version} [skip ci]"
+      }
+    ],
+    "@semantic-release/github"
+  ]
+}