docs(vscode-lm): clarify VS Code LM API integration warning (#8493)

* docs(vscode-lm): clarify VS Code LM API integration blurb, provider wording, and error guidance

* fix(vscode-lm): update settings UI warning; revert package description change

* Restored

* restored

* i18n(vscode-lm): unify vscodeLmWarning text across all locales

* i18n(vscode-lm): translate vscodeLmWarning across locales

Author: hannesrudolph

webview-ui/src/i18n/locales/ca/settings.json

@@ -351,7 +351,7 @@
 		"enablePromptCachingTitle": "Enable prompt caching to improve performance and reduce costs for supported models.",
 		"cacheUsageNote": "Note: If you don't see cache usage, try selecting a different model and then selecting your desired model again.",
 		"vscodeLmModel": "Language Model",
-		"vscodeLmWarning": "Note: This is a very experimental integration and provider support will vary. If you get an error about a model not being supported, that's an issue on the provider's end.",
+		"vscodeLmWarning": "Note: Models accessed via the VS Code Language Model API may be wrapped or fine-tuned by the provider, so behavior can differ from using the same model directly from a typical provider or router. To use a model from the Language Model dropdown, first switch to that model and then click Accept in the Copilot Chat prompt; otherwise you may see an error such as 400 \"The requested model is not supported\".",
 		"geminiParameters": {
 			"urlContext": {
 				"title": "Enable URL context",