docs(config): add SearXNG and Browserless configuration examples (#3513)

* docs(config): add SearXNG and Browserless configuration examples

Add commented-out configuration examples for the SearXNG web search
and Browserless web fetch tools introduced in PR #3451.

- SearXNG: self-hosted metasearch engine (base_url, max_results)
- Browserless: headless Chrome renderer (base_url, token, timeout_s,
  wait_for_event, wait_for_selector, reject_resource_types, etc.)

Also bump config_version to 13 since the tool schema has new options.

* fix(config): align defaults with code and remove unconfigured keys

- SearXNG default port: 8088 (matches searxng/tools.py fallback)
- Browserless default port: 3032 (matches browserless/tools.py fallback)
- Remove wait_for_selector_timeout_ms, reject_resource_types,
  reject_request_pattern from example (not yet read from config)
- Note Docker service ports differ from code defaults

config.example.yaml

@@ -510,6 +510,16 @@ tools:
     # region: wt-wt          # wt-wt is normalized for Wikipedia when backend includes auto/all/wikipedia.
     # safesearch: moderate   # on, moderate, off
 
+  # Web search tool (uses SearXNG, self-hosted, no API key required)
+  # SearXNG is a free internet metasearch engine which aggregates results from
+  # various search services. Deploy your own instance: https://github.com/searxng/searxng
+  # For Docker deployments, use the Docker service name instead of localhost.
+  # - name: web_search
+  #   group: web
+  #   use: deerflow.community.searxng.tools:web_search_tool
+  #   base_url: http://localhost:8088   # SearXNG instance URL (default: :8088; Docker: http://searxng:8080)
+  #   max_results: 5                     # Maximum number of search results
+
   # Web search tool (uses Serper - Google Search API, requires SERPER_API_KEY)
   # Serper provides real-time Google Search results. Sign up at https://serper.dev
   # Note: set SERPER_API_KEY in your environment before starting the app, or
@@ -550,6 +560,22 @@ tools:
   #   max_results: 5
   #   # api_key: $FIRECRAWL_API_KEY
 
+  # Web fetch tool (uses Browserless - headless Chrome, self-hosted or cloud)
+  # Browserless renders pages with a real headless Chrome, ideal for JavaScript-heavy
+  # sites and SPAs. Deploy your own: https://github.com/browserless/browserless
+  # For Docker deployments, use the Docker service name instead of localhost.
+  # NOTE: Only one web_fetch provider can be active at a time.
+  # Comment out the Jina AI web_fetch entry below before enabling this one.
+  # - name: web_fetch
+  #   group: web
+  #   use: deerflow.community.browserless.tools:web_fetch_tool
+  #   base_url: http://localhost:3032    # Browserless instance URL (default: :3032; Docker: http://browserless:3000)
+  #   # token: $BROWSERLESS_TOKEN        # API token (required for Browserless Cloud; optional for self-hosted)
+  #   timeout_s: 30                       # Request timeout in seconds
+  #   # wait_for_event: "networkidle"    # Wait for a page event before returning (e.g. "load", "networkidle")
+  #   # wait_for_timeout_ms: 2000        # Extra wait after page load in milliseconds
+  #   # wait_for_selector: "article"     # CSS selector to wait for before returning
+
   # Web fetch tool (uses Exa)
   # NOTE: Only one web_fetch provider can be active at a time.
   # Comment out the Jina AI web_fetch entry below before enabling this one.