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>

chart/templates/deployment.yaml

@@ -266,6 +266,34 @@ spec:
           resources:
             {{- toYaml .Values.mcpSidecars.pgtuner.resources | nindent 12 }}
         {{- end }}
+        {{- if .Values.mcpSidecars.playwright.enabled }}
+        - name: playwright-mcp
+          image: "{{ .Values.mcpSidecars.playwright.image.repository }}:{{ .Values.mcpSidecars.playwright.image.tag }}"
+          imagePullPolicy: Always
+          args:
+            - --transport
+            - sse
+            - --port
+            - {{ .Values.mcpSidecars.playwright.port | quote }}
+          ports:
+            - name: playwright
+              containerPort: {{ .Values.mcpSidecars.playwright.port }}
+          livenessProbe:
+            tcpSocket:
+              port: {{ .Values.mcpSidecars.playwright.port }}
+            initialDelaySeconds: 15
+            periodSeconds: 10
+          readinessProbe:
+            tcpSocket:
+              port: {{ .Values.mcpSidecars.playwright.port }}
+            initialDelaySeconds: 10
+            periodSeconds: 5
+          resources:
+            {{- toYaml .Values.mcpSidecars.playwright.resources | nindent 12 }}
+          securityContext:
+            runAsUser: 1000
+            runAsGroup: 1000
+        {{- end }}
       volumes:
         - name: workspace
           emptyDir: {}

chart/values.yaml

@@ -125,7 +125,7 @@ mcpSidecars:
     enabled: false  # Disabled by default, requires DATABASE_URI in secrets
     image:
       repository: dog830228/pgtuner_mcp
-      tag: latest  # TODO: pin to specific version once stable release available
+      tag: latest
     port: 8085
     resources:
       requests:
@@ -134,3 +134,16 @@ mcpSidecars:
       limits:
         memory: "256Mi"
         cpu: "500m"
+  playwright:
+    enabled: true  # Enabled by default for browser automation
+    image:
+      repository: microsoft/playwright-mcp
+      tag: latest
+    port: 8086
+    resources:
+      requests:
+        memory: "128Mi"
+        cpu: "100m"
+      limits:
+        memory: "512Mi"
+        cpu: "1000m"