fix(hooks): handle thinking blocks in image analyzer response parsing

When models have thinking enabled (e.g. codex with thinking: auto), the
API returns content as [{ type: 'thinking', thinking: '...' }, { type:
'text', text: '...' }]. The hook reads content[0].text which is
undefined for thinking blocks, causing 'No text content in response'
errors that block the Read tool (exit 2).

Also fix cross-provider model fallback: getModelsToTry() unconditionally
appends DEFAULT_MODEL (gemini-2.5-flash) as retry, which 502s on
non-gemini provider routes (e.g. codex). Only use DEFAULT_MODEL when no
provider-specific model is configured.

Fixes: content[0].text -> content.find(b => b.type === 'text')
Fixes: cross-provider retry causing 'unknown provider' 502
Ref: #511

lib/hooks/image-analyzer-transformer.cjs

@@ -177,16 +177,16 @@ function getModelsToTry() {
     seen.add(providerModels[currentProvider]);
   }
 
-  // 2. Default model
+  // 2. Default model — only when no provider-specific model is configured,
-  if (!seen.has(DEFAULT_MODEL)) {
+  // since DEFAULT_MODEL (gemini-2.5-flash) may not be routable on the
+  // current provider's CLIProxy endpoint (e.g. codex, claude)
+  if (models.length === 0 && !seen.has(DEFAULT_MODEL)) {
     models.push(DEFAULT_MODEL);
     seen.add(DEFAULT_MODEL);
   }
 
-  // 3. ANTHROPIC_MODEL fallback
+  // 3. ANTHROPIC_MODEL fallback — skip, the main chat model is not
-  if (anthropicModel && !seen.has(anthropicModel)) {
+  // necessarily vision-capable and adds unnecessary retry latency
-    models.push(anthropicModel);
-  }
 
   return models;
 }
@@ -382,7 +382,10 @@ function analyzeViaCliProxy(base64Data, mediaType, model, timeoutMs) {
 
           try {
             const response = JSON.parse(data);
-            const text = response.content?.[0]?.text;
+            // Find the first text block — skip thinking blocks which use
+            // .thinking instead of .text (e.g. codex models with thinking enabled)
+            const textBlock = response.content?.find(b => b.type === 'text' && b.text);
+            const text = textBlock?.text;
 
             if (!text) {
               reject(new Error('No text content in response'));