refactor: Fix tag style: Use parser:"..."

[winebarrel]

see https://github.com/alecthomas/participle?tab=readme-ov-file#tag-syntax

[Copilot]

Pull request overview

This PR refactors all participle parser struct tags to use the explicit parser:"..." format instead of the implicit format. This makes the codebase more consistent with modern participle v2 conventions.

• Adds parser: prefix to all struct tag annotations for participle parser directives
• Converts double-quoted string literals to single-quoted literals within parser expressions (e.g., "*" → '*', "," → ',')

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