docs(skills): compress 74 built-in skill descriptions to <=60 chars

Target: every skill's description fits in a one-line gateway menu and
leads with trigger keywords an agent would match on. Drops filler like
'Use this skill to', 'A skill for', 'This skill provides'.

Before: max description length was 791 chars (architecture-diagram),
74 of 81 built-in skills were >60 chars.

After: max 60, mean 54, all 81 built-in skills <=60.

Rewritten with double-quoted YAML scalars to preserve Chinese/arrow
glyphs (baoyu-comic, yuanbao, youtube-content).

skills/mlops/inference/vllm/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: serving-llms-vllm
-description: Serves LLMs with high throughput using vLLM's PagedAttention and continuous batching. Use when deploying production LLM APIs, optimizing inference latency/throughput, or serving models with limited GPU memory. Supports OpenAI-compatible endpoints, quantization (GPTQ/AWQ/FP8), and tensor parallelism.
+description: "vLLM: high-throughput LLM serving, OpenAI API, quantization."
 version: 1.0.0
 author: Orchestra Research
 license: MIT