fix: group chat UX polish and model switch cleanup (#205)

* fix(chat): clamp context remaining tokens to 0 instead of showing negative

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

* fix: group chat mention popup position, timestamp style, and model switch cleanup

- Move @ mention popup above input to avoid blocking the textarea
- Fix .msg-time scoping (was nested inside .msg-header, now top-level)
- Reduce timestamp opacity and set to 12px for subtler display
- Clean up stale base_url/api_key from config.yaml on model switch

Closes #204

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

* fix: remove unused variables in GroupChatInput

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

---------

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

packages/client/src/components/hermes/group-chat/GroupChatInput.vue

@@ -90,10 +90,7 @@ function updateMentionState() {
     document.body.removeChild(mirror)
 
     dropdownX.value = rect.left + mirrorRect.width - el.scrollLeft
-    // Estimate Y based on newlines before @ and line height
-    const linesBeforeAt = text.slice(0, atPos + 1).split('\n').length - 1
-    const lineHeight = parseFloat(style.lineHeight) || parseFloat(style.fontSize) * 1.2
-    dropdownY.value = rect.top + linesBeforeAt * lineHeight - el.scrollTop + lineHeight + 4
+    dropdownY.value = rect.top - el.scrollTop - 8
 
     mentionActive.value = filteredAgents.value.length > 0
 }

packages/client/src/components/hermes/group-chat/GroupMessageItem.vue

@@ -122,12 +122,13 @@ const mentionNames = computed(() => props.agents.map(a => a.name).filter(Boolean
         color: $text-muted;
         font-style: italic;
     }
+}
 
-    .msg-time {
-        font-size: 11px;
-        color: $text-muted;
-        margin-top: 2px;
-    }
+.msg-time {
+    font-size: 12px;
+    color: var(--text-muted);
+    opacity: 0.6;
+    margin-top: 2px;
 }
 
 .msg-content {

packages/server/src/controllers/hermes/models.ts

@@ -139,6 +139,8 @@ export async function setConfigModel(ctx: any) {
     const config = await readConfigYaml()
     if (typeof config.model !== 'object' || config.model === null) { config.model = {} }
     config.model.default = defaultModel
+    delete config.model.base_url
+    delete config.model.api_key
     if (reqProvider) { config.model.provider = reqProvider }
     await writeConfigYaml(config)
     ctx.body = { success: true }