fix: prevent truncated Ollama answers

backend/README.md

@@ -1100,6 +1100,7 @@ OLLAMA_BASE_URL=http://host.docker.internal:11434
 OLLAMA_DEFAULT_MODEL=qwen3.5:9b
 OLLAMA_TIMEOUT_SECONDS=120
 OLLAMA_MAX_OUTPUT_TOKENS=700
+OLLAMA_CONTEXT_TOKENS=16384
 ```
 
 The Unraid deployment adds `host.docker.internal:host-gateway` automatically.
@@ -1107,7 +1108,9 @@ Verify the connection with `GET /api/v1/assistant/status`, inspect installed
 models with `GET /api/v1/assistant/models` and ask a grounded question through
 `POST /api/v1/projects/{project_id}/assistant/query`. A requested model must be
 present in Ollama `/api/tags`. Missing water depth/bathymetry remains explicit;
-the assistant cannot turn 2D water geometry into volume.
+the assistant cannot turn 2D water geometry into volume. GeoIntel rejects an
+answer when Ollama reports `done_reason=length`, so a visibly truncated sentence
+is never presented as a complete result.
 
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