Display model, behavior, agent and usage based on server config/updated message

[joaopluigi]

Context

• Introduced a new eca.State object for centralized state management, passed to the mediator for accessing configuration, usage, and tool information.
• The mediator now exposes methods for retrieving selected model/behavior, token/cost/session info, and tool lists.
• Added a new config container to the sidebar, displaying selected model, behavior, and MCP count.
• Refactored usage info display logic to properly works with the server message and also moved status there.
• Added the EcaServerMessages user command, enabling users to interactively inspect messages sent to and received from the ECA server via a picker interface.

Before

After

[Copilot]

Pull Request Overview

This PR introduces centralized state management for the ECA plugin with real-time display updates based on server messages. The changes create a new State object that tracks configuration, usage, and tool information, while refactoring the sidebar to display this data dynamically.

• Implements centralized state management via new eca.State object
• Refactors sidebar to display model/behavior selection and MCP count in a config container
• Moves usage and status information to a combined usage container with extmarks

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
lua/eca/state.lua	New state management module handling server message processing and configuration tracking
lua/eca/sidebar.lua	Major refactor replacing status container with config container and updating usage display logic
lua/eca/server.lua	Minor cleanup removing unused capabilities field and fixing message tracking
lua/eca/observer.lua	Updates subscription ID type from integer to string
lua/eca/mediator.lua	Adds state dependency and accessor methods for configuration and usage data
lua/eca/init.lua	Integrates state object initialization with mediator
lua/eca/commands.lua	Adds new EcaServerMessages command for debugging server communication

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[ericdallo]

That looks amazing!