feat(llm): switch to DFlash2 speculative decoding, drop qwen-classifier

Replace MTP with draft-dflash and a separate DFlash2 drafter GGUF.
Remove the qwen-classifier backend to free VRAM (GPU was at 100%).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/network-access.md

@@ -22,7 +22,7 @@ Terms as defined in [`CONTEXT.md`](../CONTEXT.md). The stack doesn't run its own
 
 ## Backends
 
-`llama-server` and `qwen-classifier` publish no host port (`expose` only). They have no authentication, so they're reachable only on the stack's Docker network, through the gateway. Making them directly reachable would put an unauthenticated inference endpoint on the network. That's a deliberate security change, not a config tweak.
+`llama-server` publishes no host port (`expose` only). It has no authentication, so it's reachable only on the stack's Docker network, through the gateway. Making it directly reachable would put an unauthenticated inference endpoint on the network. That's a deliberate security change, not a config tweak.
 
 ## qdrant