chore(model gallery): 🤖 add 1 new models via gallery agent

[localai-org-maint-bot]

This PR was automatically created by the gallery agent workflow.

Summary:

• Search Term: GGUF
• Models Found: 15
• Models Added: 1
• Quantization: Q4_K_M
• Processing Time: 3.688426117s

Added Models:

• unsloth/Qwen3.8-27B-GGUF

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by leaving a comment with one of:

• /gallery-agent recreate — close this PR; the next scheduled
  run will propose this model again (useful if the entry needs
  to be regenerated with fresh metadata).
• /gallery-agent blacklist — close this PR and permanently
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Workflow Details:

• Triggered by: schedule
• Run ID: 33391903405
• Commit: 69a5b54c0afba5509bd497431c76b808200c1820

[localai-org-maint-bot]

Review pass. Entry verifies clean. One nit and one coordination note.

Nit: the entry configures spec_type:draft-mtp in overrides.options but is tagged only llm/gguf, not mtp. Per .agents/adding-gallery-models.md it should carry the tag. No ranking impact today since it is not in a variants list, but the rule exists so later variant work reads correctly. Same nit on #11813, #11820, #11847 and #11848.

Merge ordering: this is one of 11 open gallery PRs that all insert at the very top of gallery/index.yaml (hunk @@ -1,4 @@, right after ---). They conflict with each other pairwise, so they need to land one at a time with a rebase between each. The full set: #11538, #11642, #11731, #11785, #11805, #11813, #11820, #11832, #11841, #11847, #11848.