chat: surface all OpenCode models (drop the curated allow-list)

Removes the Big Pickle + Claude Haiku allow-list; the picker now lists every model
the fixed server reports from GET /config/providers.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/servers/api/chat/list-models.ts

@@ -8,9 +8,6 @@ const CLAUDE_CODE_MODELS: ModelInfo[] = [
   { id: 'claude-code/haiku', name: 'haiku', provider: 'claude-code', contextWindow: 200000, maxTokens: 8192, reasoning: false, images: true },
 ];
 
-// Curated OpenCode models to surface in the picker (the full catalog is ~58 entries).
-const OPENCODE_ALLOWLIST = new Set(['opencode/big-pickle', 'opencode/claude-haiku-4-5']);
-
 // Cache the OpenCode catalog; it's stable for a session.
 let openCodeCache: ModelInfo[] | null = null;
 
@@ -36,10 +33,8 @@ async function listOpenCodeModels(): Promise<ModelInfo[]> {
     for (const provider of data.providers ?? []) {
       const providerId = provider.id ?? '';
       for (const modelId of Object.keys(provider.models ?? {})) {
-        const full = `${providerId}/${modelId}`;
-        if (!OPENCODE_ALLOWLIST.has(full)) continue;
         models.push({
-          id: full,
+          id: `${providerId}/${modelId}`,
           name: modelId,
           provider: providerId,
           contextWindow: 200000,