fix(global-images): quote model variable in LLM check

[cjb1234567]

Summary

Fixes the interactive start-all.sh LLM connectivity check under UTF-8 locales by using ${model} before full-width Chinese punctuation.

Without braces, Bash with set -u can parse the punctuation as part of the variable name when the configured model is absent from the OpenAI /models response, terminating the startup flow with an unbound-variable error.

Validation

• Reproduced the original failure using a mocked HTTP 200 /models response without the configured model.
• Re-ran the same reproduction after the change; it completes successfully.
• Ran bash -n deploy/global-images/_lib.sh deploy/global-images/start-all.sh.

Closes #1191.

[Maxwell-Code07]

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