Add MCP registry metadata (server.json + mcpName)

[jdrhyne]

Summary

• Adds server.json at the repo root and an mcpName field to package.json, the two things required to publish this server to the official MCP registry (registry.modelcontextprotocol.io).
• Namespace: io.github.PSPDFKit/nutrient-dws-mcp-server (GitHub-auth — anyone with push to this repo can publish).
• No runtime code changed. Metadata only.

Why

Publishing once to the official registry cascades automatically to Glama, PulseMCP, and mcp.so (they auto-ingest from it), so it's the single highest-leverage discovery action for agent developers. Today this server has no server.json, so it isn't in the official registry.

Before publishing (maintainer checklist)

The publish itself is a separate step run by someone with npm + GitHub org rights:

brew install mcp-publisher
mcp-publisher login github        # needs push access to PSPDFKit
mcp-publisher publish --dry-run   # validates server.json + schema + version
mcp-publisher publish

Please confirm at dry-run time:

• version in server.json (0.1.0) matches the npm version being published.
• $schema date is current (dry-run will flag if stale).
• env var list is complete — I included NUTRIENT_DWS_API_KEY (optional/secret) and SANDBOX_PATH (optional); add others if the server reads more.

Test plan

• package.json and server.json both parse as valid JSON.
• Diff is metadata-only (package.json +1 line, new server.json).
• mcp-publisher publish --dry-run passes (run by a maintainer with the CLI).