frank-default-large: fix STRIX_LEAN model paths + add mmproj

The env file had the old STRIX paths (directory doesn't exist on disk).
Updated to the actual running STRIX_LEAN (Uncensored) variant:
- MODEL_DIR → kingjones-Qwen3.8-Flash-Next-Uncensored-ROCmFP4-STRIX_LEAN
- MODEL_FILE → 3-shard Q4_0 (00001-of-00003)
- MMPROJ_PATH → mmproj-Qwen3.8-Flash-Next-Uncensored-BF16.gguf
- serve-frank-large.sh: add --mmproj $MMPROJ_PATH

Reconciles the uncommitted local changes that were on Dankclaw.

scripts/serve-frank-large.sh

@@ -161,4 +161,5 @@ exec /usr/bin/env \
     --reasoning "$REASONING" \
     --reasoning-format "$REASONING_FORMAT" \
     --reasoning-budget -1 \
+    --mmproj "$MMPROJ_PATH" \
     "${SPEC_ARGS[@]}"