Align apply_patch behavior with Codex implementation

[rogeralsing]

Summary

• extend the internal apply_patch parser to recognize delete operations, move directives, and richer option handling so it matches the Codex reference behavior
• rewrite apply_patch execution to apply each operation immediately, support file moves/deletions, enforce newline handling, and preserve partial changes on failure
• add comprehensive tests covering deletes, moves, add-overwrite flows, newline expectations, and partial-success scenarios

Testing

• go test ./...

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https://chatgpt.com/codex/tasks/task_e_68fe00f302048328afc31b34df1453e0