feat(community): add Brave Search web search tool (#3528)

* feat(community): add Brave Search web search tool

Add a community web_search provider backed by the official Brave Search
API (https://api.search.brave.com/res/v1/web/search). API key is read
from the tool config (inline api_key) or the BRAVE_SEARCH_API_KEY env
var. Output schema (title/url/content) matches existing search tools.
No new dependencies (uses the existing httpx). Also wires up the setup
wizard, doctor health check, config example, and EN/ZH docs.

* refactor(community): drop redundant [:count] slice in Brave search

The Brave API already caps results via the `count` request param, so
client-side slicing was redundant. Tests now simulate the API honoring
`count` instead of relying on the slice. Addresses PR review nit.

* style(tests): apply ruff format to test_doctor.py

Collapse multiline write_text calls onto single lines to satisfy the
CI ruff formatter (lint-backend was failing on format --check).

scripts/doctor.py

@@ -457,8 +457,9 @@ def check_web_tool(config_path: Path, *, tool_name: str, label: str) -> CheckRes
 
         data = _load_yaml_file(config_path)
 
-        tool_uses = [t.get("use", "") for t in data.get("tools", []) if t.get("name") == tool_name]
-        if not tool_uses:
+        tool_entries = [t for t in data.get("tools", []) if t.get("name") == tool_name]
+        tool_uses = [t.get("use", "") for t in tool_entries]
+        if not tool_entries:
             return CheckResult(
                 label,
                 "warn",
@@ -476,6 +477,7 @@ def check_web_tool(config_path: Path, *, tool_name: str, label: str) -> CheckRes
                 "infoquest": "INFOQUEST_API_KEY",
                 "exa": "EXA_API_KEY",
                 "firecrawl": "FIRECRAWL_API_KEY",
+                "brave": "BRAVE_SEARCH_API_KEY",
             },
             "web_fetch": {
                 "infoquest": "INFOQUEST_API_KEY",
@@ -484,14 +486,24 @@ def check_web_tool(config_path: Path, *, tool_name: str, label: str) -> CheckRes
             },
         }
 
-        for use in tool_uses:
+        for tool_entry in tool_entries:
+            use = tool_entry.get("use", "")
             for provider, detail in free_providers.get(tool_name, {}).items():
                 if provider in use:
                     return CheckResult(label, "ok", detail)
 
-        for use in tool_uses:
+        for tool_entry in tool_entries:
+            use = tool_entry.get("use", "")
             for provider, var in key_providers.get(tool_name, {}).items():
                 if provider in use:
+                    configured_key = tool_entry.get("api_key")
+                    if isinstance(configured_key, str) and configured_key.strip():
+                        if configured_key.startswith("$"):
+                            ref_var = configured_key[1:]
+                            if os.environ.get(ref_var):
+                                return CheckResult(label, "ok", f"{provider} ({ref_var} set via api_key)")
+                        else:
+                            return CheckResult(label, "ok", f"{provider} (api_key configured)")
                     val = os.environ.get(var)
                     if val:
                         return CheckResult(label, "ok", f"{provider} ({var} set)")

scripts/wizard/providers.py

@@ -510,6 +510,14 @@ SEARCH_PROVIDERS: list[SearchProvider] = [
         env_var="FIRECRAWL_API_KEY",
         extra_config={"max_results": 5},
     ),
+    SearchProvider(
+        name="brave",
+        display_name="Brave Search",
+        description="Independent index, official API, API key required",
+        use="deerflow.community.brave.tools:web_search_tool",
+        env_var="BRAVE_SEARCH_API_KEY",
+        extra_config={"max_results": 5},
+    ),
 ]
 
 WEB_FETCH_PROVIDERS: list[WebProvider] = [