feat(plugins): add MCP server + 4 new plugin bundles (Windsurf, Cline, Continue, VS Code)

MCP Server (semantica/mcp_server.py):
- Full stdio-based MCP server compatible with Claude Desktop, Windsurf,
  Cline, Continue, VS Code, Roo Code, and any MCP-aware tool
- 12 tools: extract_entities, extract_relations, record_decision,
  query_decisions, find_precedents, get_causal_chain, add_entity,
  add_relationship, run_reasoning, get_graph_analytics, export_graph,
  get_graph_summary
- 3 resources: semantica://graph/summary, semantica://decisions/list,
  semantica://schema/info
- Lazy graph session with optional SEMANTICA_KG_PATH env var
- JSON-RPC 2.0 over stdin/stdout; run with: python -m semantica.mcp_server

New plugin bundles (each: plugin.json + marketplace.json + README.md):
- plugins/.windsurf-plugin/ — Windsurf MCP config + 17 skills + 3 agents
- plugins/.cline-plugin/    — Cline MCP config + 17 skills + 3 agents
- plugins/.continue-plugin/ — Continue MCP config + 17 skills + 3 agents
- plugins/.vscode-plugin/   — VS Code MCP config + 17 skills + 3 agents

Updated plugins/.claude-plugin/README.md:
- Platform support table expanded to 9 tools
- Full MCP server section: per-tool config snippets for Claude Desktop,
  Windsurf, Cline, Continue, VS Code; tool/resource reference tables;
  environment variables

Updated README.md:
- Hero line updated to mention MCP server
- Visual grid: Windsurf/VS Code/Cline/Continue → 'MCP server + plugin';
  Claude Desktop → 'MCP server'
- Plugin Bundles section: expanded table listing all 7 bundles with dirs
- New MCP Server section with quick-start snippet and tool/resource list
- Detailed integrations table: corrected connection types and config paths

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

plugins/.vscode-plugin/README.md

@@ -0,0 +1,36 @@
+# Semantica — VS Code Plugin
+
+Adds Semantica as an MCP server to VS Code (via GitHub Copilot Chat or any MCP-aware extension).
+
+## MCP Server Setup
+
+Add to your VS Code `settings.json`:
+
+```json
+{
+  "github.copilot.chat.mcp.servers": {
+    "semantica": {
+      "command": "python",
+      "args": ["-m", "semantica.mcp_server"]
+    }
+  }
+}
+```
+
+Or if using the VS Code MCP extension directly:
+
+```json
+{
+  "mcp.servers": {
+    "semantica": {
+      "command": "python",
+      "args": ["-m", "semantica.mcp_server"]
+    }
+  }
+}
+```
+
+## Requirements
+
+- Python 3.8+
+- `pip install semantica`

plugins/.vscode-plugin/marketplace.json

@@ -0,0 +1,17 @@
+{
+  "name": "semantica-vscode",
+  "plugins": [
+    {
+      "name": "semantica",
+      "description": "Semantica plugin for VS Code: knowledge graph skills, reasoning, extraction, and visualization.",
+      "source": "./",
+      "category": "Productivity",
+      "tags": [
+        "knowledge-graph",
+        "reasoning",
+        "semantica",
+        "vscode"
+      ]
+    }
+  ]
+}

plugins/.vscode-plugin/plugin.json

@@ -0,0 +1,35 @@
+{
+  "name": "semantica-vscode",
+  "displayName": "Semantica VS Code Plugin",
+  "description": "Semantica plugin for VS Code: knowledge graph skills, decision intelligence, reasoning, extraction, and visualization via MCP server.",
+  "version": "0.1.0",
+  "author": {
+    "name": "Semantica Contributors"
+  },
+  "homepage": "https://github.com/Hawksight-AI/semantica",
+  "repository": "https://github.com/Hawksight-AI/semantica",
+  "license": "MIT",
+  "keywords": [
+    "semantica",
+    "knowledge graph",
+    "vscode",
+    "context graphs",
+    "decision intelligence",
+    "explainability",
+    "causal analysis",
+    "provenance",
+    "ontology",
+    "graph analytics",
+    "semantic extraction",
+    "visualization",
+    "reasoning",
+    "mcp"
+  ],
+  "skills": "../skills",
+  "agents": "../agents",
+  "hooks": "../hooks/hooks.json",
+  "mcp": {
+    "server": "python -m semantica.mcp_server",
+    "transport": "stdio"
+  }
+}