feat: add Fetch and Sequential Thinking MCP sidecars

Add two new MCP (Model Context Protocol) sidecars to enable web content fetching
and structured problem-solving capabilities:

- **Fetch MCP**: Web content fetching and HTML to markdown conversion on port 8082
- **Sequential Thinking MCP**: Structured thinking and problem-solving processes on port 8083

Both sidecars are enabled by default and use the official MCP Docker images
(mcp/fetch and mcp/sequentialthinking) with fastmcp SSE transport.

Changes:
- Add fetch and sequentialthinking sidecars to values.yaml
- Add sidecar containers to deployment.yaml template
- Update .mcp.json with new server endpoints
- Update CLAUDE.md documentation with new sidecar details

Closes #43, #44

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/settings.local.json

@@ -2,6 +2,8 @@
   "enabledMcpjsonServers": [
     "kubernetes",
     "flux",
-    "playwright"
+    "playwright",
+    "github",
+    "pgtuner"
   ]
 }