feat(integrations): add OpenClaw plugin and integration module (#460)

- Add integrations/openclaw/ with OpenClawKGTool (REST) and
  OpenClawMCPConfig (mcporter.json generator)
- Add plugins/.openclaw-plugin/ bundle (plugin.json, marketplace.json,
  README) with MCP + native tool support
- Add OpenClaw badge to README header
- Reorganize "Works With Every AI Tool" table into labeled groups:
  Native Plugin Bundle, MCP Server + Plugin, MCP Server, REST API

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

integrations/openclaw/__init__.py

@@ -0,0 +1,57 @@
+"""
+Semantica × OpenClaw Integration
+==================================
+
+First-class integration between the Semantica semantic intelligence stack and
+`OpenClaw <https://openclaw.ai>`_ — the open-source personal AI agent platform.
+
+OpenClaw connects to external tools via MCP (Model Context Protocol).  This
+integration exposes the full Semantica MCP surface (12 tools, 3 resources) to
+any OpenClaw agent and also ships a lightweight ``OpenClawKGTool`` that can be
+dropped directly into an OpenClaw SOUL.md tool-list as a native tool.
+
+Public surface
+--------------
+OpenClawKGTool      — Thin wrapper around the Semantica REST API usable as an
+                       OpenClaw native tool (no MCP gateway required)
+OpenClawMCPConfig   — Helper that emits the ``mcporter.json`` snippet needed to
+                       wire Semantica's MCP server into an OpenClaw gateway
+
+Quick start
+-----------
+    pip install semantica
+
+    >>> from integrations.openclaw import OpenClawKGTool, OpenClawMCPConfig
+    >>> print(OpenClawMCPConfig().to_json())   # paste into mcporter.json
+    >>> tool = OpenClawKGTool(base_url="http://localhost:8000")
+    >>> result = tool.extract("OpenClaw is an open-source AI agent framework.")
+
+MCP quick start
+---------------
+Run the Semantica MCP server once::
+
+    python -m semantica.mcp_server
+
+Then add the printed config snippet to your OpenClaw ``mcporter.json`` and
+restart the OpenClaw Gateway::
+
+    openclaw gateway restart
+
+All 12 Semantica tools are then available as native OpenClaw agent tools.
+
+Compatibility
+-------------
+Requires ``semantica >= 0.3.0``.  The MCP path requires ``python >= 3.8`` and
+a running ``semantica.mcp_server`` instance.  The REST path requires a running
+``semantica.server`` instance (``python -m semantica.server``, port 8000 by
+default).
+"""
+
+from .mcp_tool import OpenClawKGTool, OpenClawMCPConfig
+
+__all__ = [
+    "OpenClawKGTool",
+    "OpenClawMCPConfig",
+]
+
+__version__ = "0.1.0"