feat: raise OnTeamChanged for AppTeamChanged broadcasts

[HandyS11]

Problem

The AppBroadcast.team_changed variant (proto field 4, AppTeamChanged) was defined and code-generated, but RustPlus.ParseNotification had no branch for it — so every team-snapshot change broadcast fell straight through to Logger.LogUnknownBroadcast(broadcast) and was silently dropped. Unlike the five sibling broadcasts (EntityChanged, TeamMessage, ClanMessage, ClanChanged, CameraRays), the entire vertical slice was missing.

Fix

Mirrors the existing ClanChanged pattern end-to-end:

Area	Change
Model	New TeamChangedEventArg record — PlayerId (ulong) + TeamInfo?
Mapper	New AppTeamChanged.ToTeamChangedEvent() (reuses existing ToTeamInfo())
Client	New OnTeamChanged event + dispatch branch in ParseNotification
Contract	OnTeamChanged declared on IRustPlus
Docs	Added to the events table in rustplus-client.md
Sample	LiveEvents console feature now subscribes to OnTeamChanged

Tests

• TeamInfoMapperTests.ToTeamChangedEvent_MapsPlayerIdAndTeamInfo
• RustPlusParseNotificationTests.TeamChanged_WithSubscriber_InvokesHandler
• RustPlusParseNotificationTests.TeamChanged_NoSubscriber_DoesNotThrow

Both dispatch branches (subscriber / no-subscriber) and the mapper are covered.

Verification

• dotnet build RustPlusApi.sln — clean (TreatWarningsAsErrors)
• Unit tests pass on the net10.0 host (132 passed). The net8.0 runtime (netstandard2.0 build) isn't installed locally; CI covers both TFMs. The touched code has no #if forks.
• ReSharper pre-push formatting check passed.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds first-class support for the AppBroadcast.team_changed (AppTeamChanged) broadcast in the core RustPlusApi client, exposing it as a new OnTeamChanged event with model mapping and unit test coverage (plus sample + docs updates).

Changes:

• Introduced TeamChangedEventArg, AppTeamChanged.ToTeamChangedEvent(), and a new RustPlus.OnTeamChanged dispatch branch in ParseNotification.
• Extended the public IRustPlus contract with OnTeamChanged, and updated docs + console sample to surface the new event.
• Added unit tests covering both mapper correctness and subscriber/no-subscriber dispatch behavior.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/RustPlusApi.UnitTests/TeamInfoMapperTests.cs	Adds mapper test for AppTeamChanged → TeamChangedEventArg.
tests/RustPlusApi.UnitTests/RustPlusParseNotificationTests.cs	Adds notification-dispatch tests for the new TeamChanged branch.
src/RustPlusApi/RustPlus.cs	Adds OnTeamChanged event and dispatch branch in ParseNotification.
src/RustPlusApi/Interfaces/IRustPlus.cs	Exposes OnTeamChanged on the public interface contract.
src/RustPlusApi/Extensions/AppTeamInfoToModel.cs	Adds ToTeamChangedEvent() mapping extension.
src/RustPlusApi/Data/Events/TeamChangedEventArg.cs	Introduces new event-arg type for team snapshot changes.
samples/RustPlus.ConsoleApp/Features/LiveEvents.cs	Subscribes to and displays OnTeamChanged in the sample console app.
docs/articles/rustplus-client.md	Documents the new public event in the events table.

[HandyS11]

Correct that adding an interface member is source-breaking for external implementers, but this follows the established convention of the library: all seven existing broadcast events (OnEntityChanged, OnSmartDeviceTriggered, OnStorageMonitorTriggered, OnTeamChatReceived, OnClanChatReceived, OnClanChanged, OnCameraRaysReceived) are declared directly on IRustPlus — OnEntityChanged was added the same way in #95. IRustPlus is the single canonical contract here; introducing a separate IRustPlusTeamChangedEvents would fragment it and break that consistency for no real gain while the package is still in beta. Keeping it on IRustPlus intentionally.

[HandyS11]

This is a false positive — the code compiles as-is (clean build + all unit tests pass). TeamInfo lives in RustPlusApi.Data, and this file's namespace is RustPlusApi.Data.Events, a child namespace, so the parent RustPlusApi.Data is already in scope for name resolution. ClanChangedEventArg needs its explicit using RustPlusApi.Data.Clans only because ClanInfo sits in a sibling namespace, not an ancestor. Adding using RustPlusApi.Data; here would be a redundant using directive that the ReSharper cleanup profile strips. No change needed.