Add reusable Forgejo Actions

Composite actions for CI/CD workflows:
- checkout: Clone repo with configurable depth
- docker-build: Build Docker images with multiple tags
- docker-push: Push to Forgejo Packages registry
- create-tag: Auto-increment semantic version tags
- create-issue: Create issues via Forgejo API
- create-pr: Create pull requests via Forgejo API
- comment-pr: Add comments to PRs via Forgejo API

All actions use shell scripts (no Node.js required).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

checkout/action.yaml

@@ -0,0 +1,28 @@
+name: Checkout
+description: Clone repository with configurable depth
+
+inputs:
+  repository:
+    description: Repository to clone (owner/repo)
+    default: ${{ github.repository }}
+  ref:
+    description: Branch, tag, or SHA to checkout
+    default: ${{ github.ref_name }}
+  depth:
+    description: Clone depth (0 for full history)
+    default: '1'
+  token:
+    description: Token for private repositories
+    default: ${{ github.token }}
+
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      run: |
+        if [ "${{ inputs.depth }}" = "0" ]; then
+          git clone "https://oauth2:${{ inputs.token }}@code.flowmade.one/${{ inputs.repository }}.git" .
+        else
+          git clone --depth "${{ inputs.depth }}" --branch "${{ inputs.ref }}" \
+            "https://oauth2:${{ inputs.token }}@code.flowmade.one/${{ inputs.repository }}.git" .
+        fi