fix(registry): server.json — existing image tag v0.4.0 + stdio docker flags

[temrjan]

Prep for publishing to the official MCP Registry (registry.modelcontextprotocol.io).

What

• identifier: ghcr.io/rustok-org/rustok-wallet:0.3.2 → :v0.4.0. The 0.3.2 tag does not exist on GHCR (published tags: latest, v0, v0.1, v0.1.0, v0.1.1, v0.1.2, v0.4.0); publish validation would fail or produce a dead record.
• version / packages[0].version: 0.3.2 → 0.4.0 to match the referenced image.
• Added -i --rm --init to runtimeArguments — same flags as the documented docker run in README/SKILL.md; without -i the stdio transport gets a closed stdin if the client doesn't add it itself.

Verified

• uvx check-jsonschema --schemafile …/2025-12-11/server.schema.json server.json → ok.
• Ownership label io.modelcontextprotocol.server.name already present in the v0.4.0 image config on GHCR (matches name here).
• Registry search for io.github.rustok-org/rustok-wallet → count 0 (no duplicate).

After merge: mcp-publisher login github (device flow) + mcp-publisher publish from repo root.