chat : Fix Muse Glimmer tool-call first parser error

[NickM-27]

Overview

This PR fixes an error with Muse Glimmer when the turn started immediately as a tool call with no reasoning step.

Additional information

fixes #29240

This is similar to an behavior that GPT-OSS has and is handled by the parser

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure: YES, used Opus 5 to diagnose the issue and implement the fix + a test to validate it.

[ggml-gh-bot]

Hi @NickM-27, thanks for your contribution!

Per our contribution guidelines, the automated PR checker found the following issue(s) that need your attention:

• Multiple open PRs from a new contributor: We limit new contributors (those without a previously merged PR) to 1 open PR at a time. You currently have 2 open PRs.

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[NickM-27]

Happy to mark this as a draft if desired, but to be clear I do already have a PR merged that has been merged.

[aldehir]

You can condense this to one rule:

-              "^( to=(?!self<\\|message\\|>)(?!user<\\|message\\|>)[^<]*?<\\|message\\|>)" },
-            { COMMON_GRAMMAR_TRIGGER_TYPE_PATTERN,
-              "<\\|start\\|>assistant( to=(?!self<\\|message\\|>)(?!user<\\|message\\|>)[^<]*?<\\|message\\|>)" },
+              "(?:^|<\\|start\\|>assistant)( to=(?!self<\\|message\\|>)(?!user<\\|message\\|>)[^<]*?<\\|message\\|>)" },

[aldehir]

Thank you!