docs: add patcher.config.example.json with placeholder credentials

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

claude/patcher.config.example.json

@@ -0,0 +1,26 @@
+{
+  "base_url": "https://your-api-endpoint.example.com",
+  "api_key": "YOUR_API_KEY",
+  "model": "claude-opus-4-6",
+  "models": [
+    "claude-opus-4-6",
+    "claude-sonnet-4-6",
+    "gpt-5.3-codex",
+    "gpt-5.2-codex",
+    "claude-opus-4-5-20251101",
+    "claude-sonnet-4-5-20250929",
+    "gemini-3-pro-preview",
+    "gemini-3-flash-preview",
+    "qwen3-coder-plus",
+    "qwen3-coder-flash",
+    "qwen3.5-coder-plus",
+    "glm-5",
+    "glm-4.7"
+  ],
+  "default_sonnet_model": "claude-sonnet-4-6",
+  "default_opus_model": "claude-opus-4-6",
+  "timeout_ms": 3000000,
+  "theme": "dark",
+  "complete_onboarding": true,
+  "target_version": "2.1.50"
+}