fix(web,llm): address review — document the card contract, pin the host diagnosis, gate the probe

packages/client/ui-models/src/client/CustomProviderCard.tsx

@@ -215,7 +215,12 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
           disabled={disabled}
           onChange={(event) => { setKeyDraft(event.target.value) }}
         />
-        {keyFailure === undefined ? null : <p className={styles['error']}>{t(keyFailure)}</p>}
+        {/* A create card has no stored key to keep, so the blank case says
+            what a blank field means here instead: this route may authenticate
+            through the provider's own ambient discovery or OAuth. */}
+        {keyFailure === undefined
+          ? null
+          : <p className={styles['error']}>{t(keyFailure === 'keyBlank' ? 'keyBlankNew' : keyFailure)}</p>}
       </div>
       <ModelListEditor
         models={models}
@@ -226,6 +231,7 @@ export function CustomProviderCard(props: CustomProviderCardProps): ReactNode {
           api: protocol,
           ...keyValue.length === 0 ? {} : { apiKey: keyValue },
         }}
+        probeBlocked={keyFailure === 'keyBlank' ? 'keyBlankNew' : keyFailure}
         api={api}
         t={t}
         disabled={disabled}

packages/client/ui-models/src/client/ModelListEditor.tsx

@@ -74,6 +74,13 @@ export interface ModelListEditorProps {
   onReset?: () => void
   /** Endpoint facts for the fetch action. */
   probe: ProbeTarget
+  /**
+   * Copy key naming why the fetch action is unavailable, or `undefined` when
+   * it is. The card owns this because the key it would send is judged there:
+   * asking with a key the form has already refused spends a round trip to be
+   * told what the field already says.
+   */
+  probeBlocked?: keyof typeof en | undefined
   /** Wire face the fetch action calls. */
   api: Pick<IApiClient, 'llm'>
   /** Section copy. */
@@ -314,8 +321,10 @@ export function ModelListEditor(props: ModelListEditorProps): ReactNode {
         <button
           type="button"
           className={styles['linkButton']}
-          disabled={disabled || busy || !askable}
-          title={askable ? undefined : t('fetchNeedsBaseUrl')}
+          disabled={disabled || busy || !askable || props.probeBlocked !== undefined}
+          title={props.probeBlocked !== undefined
+            ? t(props.probeBlocked)
+            : askable ? undefined : t('fetchNeedsBaseUrl')}
           onClick={() => { void fetchModels() }}
         >
           {busy ? t('fetching') : t('fetchModels')}

packages/client/ui-models/src/client/ProviderEditor.tsx

@@ -371,7 +371,7 @@ export function ProviderEditor(props: ProviderEditorProps): ReactNode {
                   defaultMaxTokens={typeof defaultMaxTokens === 'number' ? defaultMaxTokens : undefined}
                 />
               )
-              : <ModelListEditor {...catalogProps} probe={probe} api={api} />}
+              : <ModelListEditor {...catalogProps} probe={probe} probeBlocked={keyFailure} api={api} />}
           </div>
         </details>
       </>

packages/client/ui-models/src/client/locales.ts

@@ -47,6 +47,7 @@ export const en = {
   removeModel: 'Delete model',
   modelsEmpty: 'No models will be shown in the selector. Unlisted IDs can still be sent directly.',
   keyBlank: 'Enter the API key, or leave the field empty to keep the stored one.',
+  keyBlankNew: 'Enter the API key, or leave the field empty if this provider authenticates another way.',
   keyIllegalCharacters: 'This API key is not in a valid format. Please check it.',
   keyLooksWrapped: 'Paste only the key itself — not a NAME=value line, and without surrounding quotes.',
   modelIdRequired: 'Model ID is required.',
@@ -134,6 +135,7 @@ export const zh: typeof en = {
   removeModel: '删除模型',
   modelsEmpty: '模型选择器中将不显示任何模型；目录外 ID 仍可直接发送。',
   keyBlank: '请输入 API 密钥；留空则保持已存储的密钥。',
+  keyBlankNew: '请输入 API 密钥；若该提供方以其他方式鉴权，可以留空。',
   keyIllegalCharacters: '该 API 密钥格式错误，请检查。',
   keyLooksWrapped: '请只粘贴密钥本身——不要带 NAME=value 整行，也不要带引号。',
   modelIdRequired: '模型 ID 不能为空。',