feat(tui): add provider status slot

[ousamabenyounes]

Related Issue

Resolve #2353

Problem

The configurable footer slots can show the active model name, but not its provider. This makes similarly named models from different providers difficult to distinguish at a glance.

What changed

• Add an optional provider entry to [status_line].items.
• Render the active model provider in the configured slot order without changing the default footer layout.
• Verify both configuration parsing and footer composition.
• Update the English and Chinese configuration references and add a patch changeset.

Test verification (RED → GREEN)

RED on origin/main with the regression test only:

expected "custom-provider  Model Name"
received "Model Name"

GREEN with this patch:

Test Files  2 passed (2)
Tests       33 passed (33)

Full local suite: passed.

Test Files  1034 passed | 12 skipped (1046)
Tests       16877 passed | 3 expected fail | 83 skipped | 2 todo (16965)
Build       Kimi Code package passed

Checklist

• I have read the CONTRIBUTING document.
• I have linked a related issue, or explained the problem above.
• I have added tests that prove my feature works.
• Ran gen-changesets skill, or this PR needs no changeset.
• Ran gen-docs skill, or this PR needs no doc update.

[changeset-bot]

🦋 Changeset detected

Latest commit: 1e9d342

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@moonshot-ai/kimi-code	Patch

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