Preserve EOF whitespace in apply_patch updates

[ctkm-aelf]

Changed files

Implemented EOF whitespace preservation for codex-apply-patch update hunks by keeping the original split-line representation through replacement application instead of stripping the terminal empty element and re-adding a newline unconditionally.

Updated focused CLI and scenario coverage for files without a final newline and for files with multiple trailing blank lines. The scenario fixture input was extended into scope because the regression requires a no-final-newline source fixture.

Fixes local managed issue #48.

Upstream reference: openai#21121.

Test results

Passed:

• just fmt
• bash -lc 'set -a; if test -f /Users/chronoai/Desktop/codex/.refactor-loop/host.env; then source /Users/chronoai/Desktop/codex/.refactor-loop/host.env; fi; set +a; bash "$CONSENSUS_RND_RUST_GUARD" build'
• bash -lc 'set -a; if test -f /Users/chronoai/Desktop/codex/.refactor-loop/host.env; then source /Users/chronoai/Desktop/codex/.refactor-loop/host.env; fi; set +a; bash "$CONSENSUS_RND_RUST_GUARD" test'
• just test -p codex-apply-patch
• just test -p codex-core apply_patch_cli_update_preserves
• just fix -p codex-apply-patch
• git diff --check

CI_GUARDS was empty in host configuration, so no architecture guard command was configured to run.

Deviations

HOST_REFACTOR_COMMENT_POLICY was empty and normalized to none, so no refactor self-documentation comments were added.

The fixture input path codex-rs/apply-patch/tests/fixtures/scenarios/014_update_file_appends_trailing_newline/input/no_newline.txt was modified after emitting a scope-extension record because the scenario regression depends on preserving a no-final-newline input file.

No commit was created; changes are staged in the worktree for controller-owned PR publication.

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