feat: add support for JetBrains AI Assistant MCP configuration

[besdar]

This PR adds MCP (Model Context Protocol) configuration generation support for JetBrains AI Assistant, enabling rulesync to generate .ai/mcp/mcp.json (project) and ~/.ai/mcp/mcp.json (global) from the unified .rulesync/.mcp.json source file.

Previously, JetBrains AI Assistant was the only major JetBrains tool without MCP support in rulesync. JetBrains Junie already had MCP support, and this PR brings the same capability to AI Assistant — including both project-level and global (user-level) scope.

Changes

New files

• src/features/mcp/aiassistant-mcp.ts — New AiassistantMcp class implementing MCP generation for JetBrains AI Assistant
• src/features/mcp/aiassistant-mcp.test.ts — Unit tests for AiassistantMcp

Modified files

• src/constants/aiassistant-paths.ts — Added AIASSISTANT_MCP_DIR_PATH and AIASSISTANT_MCP_FILE_NAME constants for the .ai/mcp/mcp.json path
• src/types/tool-target-tuples.ts — Added "aiassistant" to mcpProcessorToolTargetTuple
• src/features/mcp/mcp-processor.ts — Registered AiassistantMcp in the tool MCP factories map with supportsProject: true and supportsGlobal: true
• src/e2e/e2e-mcp.spec.ts — Added aiassistant to both project and global e2e MCP generation matrix tests
• README.md — Updated Supported Tools table: mcp column now shows ✅ for JetBrains AI Assistant
• docs/reference/supported-tools.md — Updated detailed supported tools reference: mcp column shows ✅ 🌏
• skills/rulesync/supported-tools.md — Updated skills-distributed supported tools reference

Generated file format

The generated .ai/mcp/mcp.json (and ~/.ai/mcp/mcp.json for global scope) follows the standard mcpServers JSON format that JetBrains AI Assistant reads natively:

{
  "mcpServers": {
    "my-server": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/dir"]
    }
  }
}

Usage

# Generate .ai/mcp/mcp.json for JetBrains AI Assistant (project scope)
rulesync generate --targets aiassistant --features mcp

# Generate ~/.ai/mcp/mcp.json for JetBrains AI Assistant (global scope)
rulesync generate --targets aiassistant --features mcp --global

# Or generate all features for AI Assistant
rulesync generate --targets aiassistant --features "*"

Scope support

Scope	Path	Supported
Project	.ai/mcp/mcp.json	✅
Global	~/.ai/mcp/mcp.json	✅

The relative path is identical for both scopes; the base directory changes (project working directory for project scope, home directory for global scope). This follows the same pattern used by JetBrains Junie.

References

• JetBrains AI Assistant MCP documentation