fix: persist OpenCode provider when saving workflow config (#377)

The POST /config/repos endpoint destructured the `provider` field from
the request body but never included it in the object passed to
addReviewRepo(), silently dropping it. This caused workflows saved with
OpenCode provider to lose their provider setting, defaulting back to
'claude' on edit.

Also adds provider inference in EditWorkflowModal for legacy configs
that have a non-Claude model but no provider field — if the model
doesn't start with 'claude-', infer provider as 'opencode'.

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

Author: alari76

server/workflow-routes.ts

@@ -324,6 +324,7 @@ export function createWorkflowRouter(
       kind,
       customPrompt,
       model,
+      provider,
     })
 
     // Re-sync schedules and commit hooks with updated config

src/components/EditWorkflowModal.tsx

@@ -33,14 +33,18 @@ interface Props {
 
 export function EditWorkflowModal({ token, repo, onClose, onSave }: Props) {
   const parsed = parseCron(repo.cronExpression)
+  // Infer provider from model when provider field is missing (legacy configs)
+  const inferredProvider: CodingProvider =
+    repo.provider ?? (repo.model && !repo.model.startsWith('claude-') ? 'opencode' : 'claude')
+
   const [form, setForm] = useState({
     kind: repo.kind ?? 'coverage.daily',
     cronHour: parsed.hour,
     cronMinute: parsed.minute,
     cronDow: parsed.dow,
     customPrompt: repo.customPrompt ?? '',
     model: repo.model ?? '',
-    provider: (repo.provider ?? 'claude') as CodingProvider,
+    provider: inferredProvider,
   })
   const [saving, setSaving] = useState(false)
   const [formError, setFormError] = useState<string | null>(null)