chore: remove Gitea configuration and references

Removed all Gitea-related files and references:
- Deleted .gitea/workflows directory (ai-review, ci, e2e, release)
- Removed gitea MCP server from .mcp.json
- Updated CLAUDE.md to list GitHub instead of Gitea
- Updated CHANGELOG.md to remove Gitea migration note

All CI/CD now runs exclusively through GitHub Actions.

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

claude.md

@@ -104,6 +104,7 @@ Additional considerations:
 ## MCP Servers
 
 The project has MCP server integrations configured in `.mcp.json`:
-- **Gitea** (git.farh.net): Source control via `gitea-mcp-server`
+- **GitHub**: Source control via `github-mcp-server`
 - **Kubernetes** (local): Cluster access via `kubernetes-mcp-server`
 - **Flux** (local): Flux Operator access via `flux-operator-mcp`
+- **Playwright**: Browser automation via `@playwright/mcp`