fix: sync ContainerNetwork gateway and DNS fields

[Shadorux]

Summary

• Add gateway and dns to the shared ContainerNetwork protocol type.
• Remove the stale commented-out mock badge from the container inspect drawer.
• Align the protocol type with the fields already sent by the agent and consumed by the web UI.

Type of change

• Bug fix
• New feature
• Refactor / cleanup
• Docs
• Infrastructure / CI
• Breaking change

Areas touched

• apps/server (NestJS)
• apps/web (React / Vite)
• apps/agent (Go)
• packages/protocol (shared WebSocket contracts)
• infrastructure / .github/workflows
• docs

Related issues

Closes #168

How to test

1. Run the relevant builds:

   npm run build --workspace=@docksight/protocol
   npm run build --workspace=@docksight/server
   npm run build --workspace=@docksight/web

2. Open a container's inspect drawer and confirm its Networks table displays the network name, IP address, gateway, and DNS values.

Checklist

• Change is focused and stays within the existing modular monolith boundaries.
• Ran the relevant checks locally (see below).
• Updated docs under docs/ if module boundaries or the protocol changed.
• Added an ADR under docs/decisions/ if this is a larger architectural change.

Local checks

# packages/protocol must be built first — apps/server and apps/web
# import it from its dist output.
npm run build --workspace=@docksight/protocol
npm run test  --workspace=@docksight/protocol

npm run build --workspace=@docksight/server
npm run lint  --workspace=@docksight/server
npm run test  --workspace=@docksight/server

npm run build --workspace=@docksight/web
npm run lint  --workspace=@docksight/web

Protocol changes

• Updated packages/protocol/src and the fixtures under packages/protocol/fixtures.
• Server, web, and agent were all updated for the new contract.
• Older agents remain compatible because this change only brings the TypeScript contract in sync with fields the agent already sends.

No wire-format behavior changes are introduced; gateway and dns are already present in the agent payload.

Screenshots

No visual behavior change.