fix: restore fetchAvailableModels to fix provider lost as custom (#194)

* fix: restore fetchAvailableModels to fix provider lost as custom (#174)

#174 replaced fetchAvailableModels with fetchConfigModels, but
config/models response lacks default_provider, label, base_url and
api_key fields. This caused selectedProvider to always be empty,
making all models appear as "custom" in the model selector.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: bump version to 0.4.6

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hermes-web-ui",
-  "version": "0.4.5",
+  "version": "0.4.6",
   "description": "Self-hosted AI chat dashboard for Hermes Agent — multi-model (Claude, GPT, Gemini, DeepSeek) web UI with Telegram, Discord, Slack, WhatsApp integration",
   "repository": {
     "type": "git",