refactor(backend): optimize [technology] snippets for deterministic Agent parsing

[beginwebdev2002]

This PR executes an autonomous audit of the backend/ directory, specifically cleaning up highly repetitive boilerplate language ("It deviates from modern deterministic standards, making the code harder for AI Agents and Senior Developers to parse and safely extend.") across multiple markdown files.

This pruning process results in much more readable and concise documentation that adheres to the "Machine-Optimal" standard outlined in the task brief without sacrificing technical context.

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PR created automatically by Jules for task 3679196253517888377 started by @beginwebdev2002

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