sap-drawio: point defaults at the live LLM host and a 16 GB-capable validator

OLLAMA_URL default was 192.168.0.32, a host that has been retired -- a fresh
install would have come up unable to reach any engine. The LLM now runs on the
Docker host, reachable from a container via the bridge gateway.

VALIDATOR_MODEL default was gemma4:31b (21.8 GB), which does not fit this
box's 16 GB card: it ran at 2.4 tok/s with 46% of the model on CPU and timed
out the validator stage at 600 s. qwen3-vl:8b fits entirely in VRAM at
44 tok/s.

Defaults only -- no fields added or removed, no required-flag changes, so no
form_fields schema migration for existing installs.

apps/sap-drawio/config.json

@@ -5,14 +5,19 @@
   "short_desc": "Turn a hand-drawn or Mermaid sketch into a polished SAP BTP draw.io diagram.",
   "author": "alexz",
   "port": 8011,
-  "categories": ["development", "utilities"],
+  "categories": [
+    "development",
+    "utilities"
+  ],
   "tipi_version": 1,
   "version": "1.0.0",
   "source": "https://git.alexzaw.dev/alexz/sap-architecture-diagrams",
   "website": "https://git.alexzaw.dev/alexz/sap-architecture-diagrams",
   "exposable": true,
   "dynamic_config": true,
-  "supported_architectures": ["amd64"],
+  "supported_architectures": [
+    "amd64"
+  ],
   "min_tipi_version": "4.0.0",
   "form_fields": [
     {
@@ -21,7 +26,7 @@
       "hint": "Ollama-compatible LLM host",
       "required": true,
       "env_variable": "OLLAMA_URL",
-      "default": "http://192.168.0.32:11434"
+      "default": "http://172.17.0.1:11434"
     },
     {
       "type": "text",
@@ -35,7 +40,7 @@
       "label": "Validator model",
       "required": true,
       "env_variable": "VALIDATOR_MODEL",
-      "default": "gemma4:31b"
+      "default": "qwen3-vl:8b"
     },
     {
       "type": "password",