ci: add mit license + validate workflow

workflow runs on push to main and all prs:
- docker compose config -q (yaml + env interpolation)
- yq extract embedded alloy config
- alloy fmt (syntax check)

alloy/.github/workflows/validate.yml

@@ -0,0 +1,33 @@
+name: validate
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    env:
+      # Dummy values so `compose config` doesn't fail on the `:?required` guards.
+      ALLOY_HOSTNAME: ci
+      PROM_URL:       https://example.com
+      PROM_USER:      "1"
+      LOKI_URL:       https://example.com
+      LOKI_USER:      "1"
+      GRAFANA_TOKEN:  x
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Validate compose YAML + env interpolation
+        run: docker compose config -q
+
+      - name: Extract embedded Alloy config
+        uses: mikefarah/yq@v4
+        with:
+          cmd: yq '.configs.alloy_config.content' docker-compose.yml > config.alloy
+
+      - name: Validate Alloy config syntax
+        run: |
+          docker run --rm -v "$PWD/config.alloy:/config.alloy:ro" \
+            grafana/alloy:v1.10.0 fmt /config.alloy > /dev/null

alloy/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 tiennm99
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.