fix(helm): update Qdrant dependency condition to match new mode structure

The Qdrant subchart was being included by default even in memory/persistent
modes. Changed the dependency condition from `qdrant.enabled` to
`qdrant.networkMode.deploySubchart` to align with the three-mode structure.

Now the Qdrant subchart is ONLY deployed when:
- qdrant.mode: "network"
- qdrant.networkMode.deploySubchart: true

Verified all three modes:
- Memory mode (:memory:): No subchart, QDRANT_LOCATION=:memory:
- Persistent mode (path): No subchart, QDRANT_LOCATION=/app/data/qdrant, PVC created
- Network mode (subchart): Qdrant subchart deployed, QDRANT_URL=http://...:6333
- Network mode (external): No subchart, QDRANT_URL=<external-url>

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

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

charts/nextcloud-mcp-server/Chart.yaml

@@ -25,7 +25,7 @@ dependencies:
   - name: qdrant
     version: "0.9.0"
     repository: https://qdrant.github.io/qdrant-helm
-    condition: qdrant.enabled
+    condition: qdrant.networkMode.deploySubchart
   - name: ollama
     version: "1.33.0"
     repository: https://otwld.github.io/ollama-helm