feat: Surface organization-enabled custom (BYOK) models

[xinyi-gong]

Summary

Organization- and enterprise-contributed BYOK models are returned by the
language server through copilot/models with a customModel payload (instead
of a providerName). This PR consumes that metadata so these models appear
automatically in the chat model picker — the user does not need to configure
their own API key.

Changes

• Protocol: add customModel (keyName, ownerName, ownerType,
  provider) to the CopilotModel type, including equals/hashCode/
  toString.
• Model picker grouping: models carrying customModel are grouped under the
  Custom Models section, and their provider is used as the picker suffix
  (mirroring BYOK models that arrive with a providerName).
• Hover: show a <model> is contributed by <owner> using <key> line in the
  model hover, matching the IntelliJ tooltip.
• i18n: add the model_hover_customModelInfo message.

Tests

• CopilotModelTests — customModel Gson deserialization (present / absent) and
  equals/hashCode coverage.
• ModelUtilsTests — suffix resolution uses customModel.provider, with
  providerName taking precedence.
• ./mvnw verify passes (checkstyle: 0 violations; all core + ui tests green).

[Copilot]

Pull request overview

This PR updates the Eclipse client to consume the language server’s new customModel metadata for organization/enterprise-contributed BYOK models so they appear automatically in the chat model picker (including grouping, suffix display, and hover details) without requiring users to configure their own API key.

Changes:

• Extend CopilotModel protocol type with a customModel payload and incorporate it into equals/hashCode/toString.
• Update model picker grouping and suffix resolution to recognize models with customModel (using its provider when providerName is absent).
• Add a localized hover line describing the contributing owner/key, plus unit tests for deserialization and suffix behavior.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtils.java	Use customModel.provider as a suffix source when providerName is absent.
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/swt/ModelHoverContentProvider.java	Render an extra hover line for contributed custom models.
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/i18n/messages.properties	Add the new localized hover message template.
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/i18n/Messages.java	Declare the new NLS message key.
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/ModelPickerGroupsBuilder.java	Group customModel-bearing models under the Custom Models section.
com.microsoft.copilot.eclipse.ui.test/src/com/microsoft/copilot/eclipse/ui/utils/ModelUtilsTests.java	Add tests for suffix selection behavior involving customModel.
com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/lsp/protocol/CopilotModel.java	Add customModel record and include it in equality/hash/toString.
com.microsoft.copilot.eclipse.core.test/src/com/microsoft/copilot/eclipse/core/lsp/protocol/CopilotModelTests.java	Add Gson deserialization + equality/hash coverage for customModel.

[jdneo]

The selected model is not same as the turn footer

[xinyi-gong]

The selected model is not same as the turn footer

Fixed: the client now sends the concrete model id (modelInfo.id) instead of only the non-unique family, so the server uses the exact selected model and the footer matches the picker.

[jdneo]

@iloveeclipse, I remember Mykola asked about the org leveled custom model, and this is it.

[iloveeclipse]

@jdneo: could you trigger a nightly build?

BTW, last ("old") nightly doesn't seem to be available anymore (yesterday it was OK):

An error occurred while collecting items to be installed
session context was:(profile=SDKProfile, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
No repository found containing: osgi.bundle,com.microsoft.copilot.eclipse.branding,0.19.0.202606300450_nightly
Can't download artifact osgi.bundle,com.microsoft.copilot.eclipse.branding,0.19.0.202606300450_nightly required by com.microsoft.copilot.eclipse.branding[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.core.agent.linux.x64[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.ui[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.branding[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.core[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.terminal.api[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.feature.feature.group[0.19.0.202606300450_nightly], com.microsoft.copilot.eclipse.ui.jobs[0.19.0.202606300450_nightly]

[jdneo]

@iloveeclipse how did you trigger this error?

It seems work on my side

[iloveeclipse]

It seems work on my side

I see the entry like yours, but if I continue with installation, the error is reported. Yesterday it was OK.