Set ollama's server-level context default to 11264, fix compose drift

The prior fix dropped numCtx to 8192 to guarantee full GPU offload,
but real multi-turn djAgentPick conversations peak around 7.5k tokens
-- leaving almost no headroom before llama.cpp's context-shift drops
the front of the prompt (system instructions + tool defs, including
`done`). Result: "agent stopped without calling done" recurring every
few picks. 11264 is the largest context that still offloads all 29
layers on this GPU (tested empirically -- 12288 fell 15MB short and
dropped to 28/29), leaving ~3.7k tokens of margin over the observed
peak.

Also: OLLAMA_CONTEXT_LENGTH had drifted onto the running container via
an earlier manual `docker run` and was never in this compose file, so
a prior git-redeploy silently kept the manual value instead of the
committed one. Committing it here closes that drift.

Claude-Session: https://claude.ai/code/session_01L7Rwa6guD5wK8F8tWQwcJX

ollama/docker-compose.yml

@@ -17,6 +17,13 @@ services:
       # attention + an explicitly quantized KV cache keep it small and stable.
       - OLLAMA_FLASH_ATTENTION=1
       - OLLAMA_KV_CACHE_TYPE=q8_0
+      # Server-level default context, kept in step with SUB/WAVE's own
+      # llm.numCtx (settings.json) -- 11264 is the largest value that still
+      # fits the full 29-layer GPU offload on this 6GB card with margin, while
+      # staying above the ~7.5k-token peak seen in real multi-turn DJ-agent
+      # calls (a lower ceiling truncates the front of the prompt -- including
+      # the tool definitions -- and the agent stops calling `done`, #291).
+      - OLLAMA_CONTEXT_LENGTH=11264
     volumes:
       - /srv/ollama:/root/.ollama
     runtime: nvidia