feat: OpenAPI and MCP from the same serve handlers (#20)

Agents get GET /openapi.json and POST /mcp. Tool names match
search/get/stats/audit paths so PicoClaw does not need shebangs.

bin/brain/serve.go

@@ -6,6 +6,9 @@
 //	KB_ROOT=/path/to/2dph ./bin/brain/serve.go
 //	KB_WORKERS=4 KB_PORT=8630 ./bin/brain/serve.go
 //
+//	GET  /openapi.json  same Ops table as the handlers
+//	POST /mcp           JSON-RPC tools/list + tools/call
+//
 // Needs CGO + libladybug (same as bin/brain/search.go).
 // NOTE: never run `gofmt -w` on this file — it breaks the shebang.
 package main

bin/tools/test_published_docs.py

@@ -67,6 +67,14 @@ class PublishedDocsTest(unittest.TestCase):
         self.assertIn("internal/brain/rank", design)
         self.assertIn("They do not exec Python", design)
 
+    def test_openapi_mcp_from_same_handlers(self) -> None:
+        plan = (ROOT / "PLAN.md").read_text()
+        self.assertIn("D20", plan)
+        self.assertIn("/openapi.json", (ROOT / "README.md").read_text())
+        self.assertIn("/mcp", (ROOT / "README.md").read_text())
+        skill = (ROOT / "skills" / "brain" / "SKILL.md").read_text()
+        self.assertIn("/mcp", skill)
+
     def test_readme_search_escalates_web(self) -> None:
         text = (ROOT / "README.md").read_text()
         self.assertIn("--no-web", text)