Feature/fix speed bottlenecks 2

[Picazsoo]

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Summary by cubic

Improve code generation speed by cutting regex overhead and disk I/O. Precompiled shared patterns and a template content cache reduce repeated work; batch runs now print total duration, with standardized changes across many generators and fixes to placeholder/path handling.

• New Features

  • Added elapsed time logging to GenerateBatch (mm ss ms).

• Refactors

  • Centralized shared precompiled regex patterns and helpers in DefaultCodegen and PatternCache; replaced many replaceAll/matches/split with cached patterns or String.replace.
  • Standardized path parameter, placeholder, and escaping logic across generators (e.g., Go/Erlang/PHP/Java/JS/Ruby), fixing edge cases and reducing backtracking.
  • Minor cleanups and correctness tweaks (immutability, consistent sanitizers like STARTS_WITH_DIGIT/ALL_UPPER_UNDERSCORE, precompiled DOT/MINUS, newline splitting).

^{Written for commit a0172e1. Summary will update on new commits.}