feat: major improvements to dev container and MCP sidecars

This commit addresses multiple GitHub issues and adds significant enhancements:

🔧 **Issue #8 - Browser Window Title Fix**
- Updated browser window title from "Antigravity Dev Container" to "Dev Container"
- Changed APP_NAME in Dockerfile and startup script for consistency

🚀 **Issue #30 - PostgreSQL Tuner MCP Sidecar**
- Added PostgreSQL performance tuning MCP sidecar (dog830228/pgtuner_mcp)
- Provides AI assistant with database analysis capabilities:
  - Slow query analysis and optimization suggestions
  - Index recommendations with HypoPG virtual testing
  - Table and index bloat detection
  - Vacuum operation tracking and health scoring
- Requires DATABASE_URI in env secret, optional PGTUNER_EXCLUDE_USERIDS
- Disabled by default, configurable via mcpSidecars.pgtuner.enabled
- Updated CLAUDE.md documentation with full configuration examples

🎭 **Playwright: Centralized Service → Sidecar Conversion**
- Converted Playwright from external service to self-contained sidecar
- Updated .mcp.json endpoint: cluster service → http://localhost:8086/sse
- Added deployment configuration with proper health checks
- Enabled by default for immediate browser automation capabilities
- Higher resource allocation (512Mi memory, 1 CPU) for browser workloads

📚 **Documentation Updates**
- Updated README.md: "Antigravity Dev Container" → "Dev Container"
- Added comprehensive MCP sidecars documentation
- Updated secret keys table with database-uri and pgtuner-exclude-userids
- Added configuration examples for all 6 MCP sidecars:
  - kubernetes-mcp (enabled)
  - flux-mcp (enabled)
  - github-mcp (disabled - archived)
  - homeassistant-mcp (disabled - needs secrets)
  - pgtuner-mcp (disabled - needs DATABASE_URI)
  - playwright-mcp (enabled - browser automation)
- Updated CLAUDE.md with complete sidecar reference table
- Added Helm deployment examples and troubleshooting

🏗️ **Architecture Improvements**
- All MCP sidecars now self-contained within pod
- Consistent SSE transport configuration across all sidecars
- Proper health checks and resource limits for all services
- Simplified deployment with no external service dependencies

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

@@ -90,13 +90,16 @@ MCP (Model Context Protocol) servers run as sidecar containers in the pod, enabl
 | `flux-mcp` | `ghcr.io/controlplaneio-fluxcd/flux-operator-mcp` | v0.41.1 | 8081 | `http://localhost:8081/sse` | Enabled |
 | `github-mcp` | `ghcr.io/modelcontextprotocol/servers/github` | latest | 8088 | `http://localhost:8088/sse` | Enabled |
 | `homeassistant-mcp` | `ghcr.io/homeassistant-ai/ha-mcp` | 6.7.1 | 8087 | `http://localhost:8087/sse` | Disabled |
+| `pgtuner-mcp` | `dog830228/pgtuner_mcp` | latest | 8085 | `http://localhost:8085/sse` | Disabled |
+| `playwright-mcp` | `microsoft/playwright-mcp` | latest | 8086 | `http://localhost:8086/sse` | Enabled |
 
 **Note:**
 - Kubernetes and Flux sidecars require `clusterAccess` != `none` to be deployed (they need RBAC permissions)
 - Kubernetes and Flux sidecars inherit the pod's ServiceAccount RBAC permissions
 - GitHub sidecar uses `GITHUB_TOKEN` from the env secret (same token used for repo cloning)
 - Home Assistant sidecar requires `HOMEASSISTANT_URL` and `HOMEASSISTANT_TOKEN` in the env secret
-- Playwright MCP remains an external service
+- PostgreSQL tuner sidecar requires `DATABASE_URI` in the env secret (PostgreSQL connection string)
+- Playwright sidecar provides browser automation and web testing capabilities
 
 #### Enabling/Disabling MCP Servers
 
@@ -113,6 +116,10 @@ mcpSidecars:
     enabled: false
   homeassistant:
     enabled: false
+  pgtuner:
+    enabled: false
+  playwright:
+    enabled: false
 
 # Or selectively enable/disable
 mcpSidecars:
@@ -124,6 +131,10 @@ mcpSidecars:
     enabled: true  # Keep GitHub MCP enabled (uses GITHUB_TOKEN)
   homeassistant:
     enabled: true  # Enable Home Assistant MCP (requires secrets)
+  pgtuner:
+    enabled: true  # Enable PostgreSQL tuner MCP (requires DATABASE_URI)
+  playwright:
+    enabled: true  # Enable Playwright MCP for browser automation
 ```
 
 When deploying via Helm: