Add Ollama provider for local LLM support

Reuses OpenAIProvider via Ollama's OpenAI-compatible API at localhost:11434.
No API key needed - just install Ollama, pull a model, and set LLM_PROVIDER=ollama.
Vision models (llava, llama3.2-vision) supported for screenshot fallback.

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

site/index.html

@@ -772,13 +772,19 @@ cp .env.example .env</pre>
       <div class="stepper-step">
         <span class="stepper-num">3</span>
         <h3>configure an llm provider</h3>
-        <p>edit <code>.env</code> - fastest way to start is groq (free tier):</p>
-<pre>LLM_PROVIDER=groq
+        <p>edit <code>.env</code> - fastest way is ollama (fully local, no api key):</p>
+<pre># local (no api key needed)
+ollama pull llama3.2
+LLM_PROVIDER=ollama
+
+# or cloud (free tier)
+LLM_PROVIDER=groq
 GROQ_API_KEY=gsk_your_key_here</pre>
         <table>
           <thead><tr><th>provider</th><th>cost</th><th>vision</th><th>notes</th></tr></thead>
           <tbody>
-            <tr><td>groq</td><td>free</td><td>no</td><td>fastest to start</td></tr>
+            <tr><td>ollama</td><td>free (local)</td><td>yes*</td><td>no api key, runs on your machine</td></tr>
+            <tr><td>groq</td><td>free</td><td>no</td><td>fastest cloud option</td></tr>
             <tr><td>openrouter</td><td>per token</td><td>yes</td><td>200+ models</td></tr>
             <tr><td>openai</td><td>per token</td><td>yes</td><td>gpt-4o</td></tr>
             <tr><td>bedrock</td><td>per token</td><td>yes</td><td>claude on aws</td></tr>
@@ -947,7 +953,7 @@ actions.ts         22 actions + adb retry
 skills.ts          6 multi-step skills
 workflow.ts        workflow orchestration
 flow.ts            yaml flow runner
-llm-providers.ts   4 providers + system prompt
+llm-providers.ts   5 providers + system prompt
 sanitizer.ts       accessibility xml parser
 config.ts          env config
 constants.ts       keycodes, coordinates