Show the serving provider in the model-info card (#2185)

* Show the serving provider in the model-info card

The model-info popup (click the model name on a message) shows the model
and pricing, with a logo inferred from the model NAME. But the same model
can be served by different endpoints — e.g. claude-haiku via OpenRouter
vs GitHub Copilot vs Anthropic direct — which the name-based logo can't
distinguish.

Add a 'Provider' line derived from the session's endpoint URL:
- new providerLabel(endpointUrl) in static/js/providers.js maps the host
  to a friendly name (GitHub Copilot, OpenRouter, Anthropic, OpenAI,
  Google, AWS Bedrock, DeepSeek, Mistral, Groq, Together, Fireworks,
  Perplexity, xAI), 'Local' for loopback/LAN, else the bare host.
- static/js/chatRenderer.js renders it under Model in the card, from
  window.sessionModule.getCurrentEndpointUrl().

* Anchor provider-label patterns to the hostname

providerLabel matched its patterns against the full endpoint URL with
unanchored substrings, so a host like max.airlines.com matched /x\.ai/ and was
mislabeled "xAI". Anchor each pattern to the end of the hostname ((^|.)domain$)
and test against the parsed host instead of the raw URL.

static/js/chatRenderer.js

@@ -4,7 +4,7 @@
 import uiModule from './ui.js';
 import markdownModule from './markdown.js';
 import { addAITTSButton } from './tts-ai.js';
-import { providerLogo } from './providers.js';
+import { providerLogo, providerLabel } from './providers.js';
 import settingsModule from './settings.js';
 import spinnerModule from './spinner.js';
 import { bindMenuDismiss } from './escMenuStack.js';
@@ -577,6 +577,12 @@ export function applyModelColor(roleEl, modelName) {
       if (logoHtml) html += '<span class="role-provider-logo" style="opacity:0.7">' + logoHtml + '</span>';
       html += short + '</div>';
       html += '<div><span class="ctx-label">Model</span> ' + modelName.split('/').pop() + '</div>';
+      // Provider = the serving endpoint, distinct from the model vendor/logo
+      // (e.g. the same model via OpenRouter vs Copilot vs Anthropic direct).
+      const _epUrl = (window.sessionModule && window.sessionModule.getCurrentEndpointUrl)
+        ? window.sessionModule.getCurrentEndpointUrl() : null;
+      const _provLabel = providerLabel(_epUrl);
+      if (_provLabel) html += '<div><span class="ctx-label">Provider</span> ' + uiModule.esc(_provLabel) + '</div>';
       // Show static context initially, then fetch real from server
       const _realCtx = window._realContextLengths && window._realContextLengths[modelName];
       if (_realCtx) {