[NopeCharon]

What and why

With diff.renames=copies, git diff reports a new file copied from a changed file with copy from / copy to extended headers. parse_unified_diff handled the equivalent rename headers but ignored these (details in #286):

• A copy was shown as modified.
• An exact copy has no --- / +++ lines. When its source and target paths contain spaces, the diff --git header cannot be split, so the canvas showed a phantom entry (src.txt with oldPath my), plus the real path again as a hunk-less entry from changed_files.

The copy headers are now read like the rename headers: status copied, oldPath from copy from, and path / newPath from copy to. The canvas displays the status as text, and no consumer branches on its value.

Fixes #286

Linked Issue for product-semantic or public-contract changes: none (routine fix)

Change class

• Routine fix, documentation, test, maintenance, or presentation-only UI
• Product-semantic or public-contract change discussed in the linked Issue
• Isolated, default-off experiment

Owning layer: server/unified_diff.py, the parser that turns git diff output into the provider-neutral diff canvas shape.

User-visible effect, or none: for users with diff.renames=copies, copied files appear once in the attempt diff canvas as copied with their real paths.

Compatibility or migration impact, or none: none. copied is a new value of the existing free-text status field; the output shape is unchanged.

Evidence

Commands and manual journeys run:

• python -m pytest -q tests/test_local_git_provider_diff.py tests/test_work_artifact_registry.py tests/test_unified_diff_canvas.py tests/test_work_export_integration.py: 63 passed (Linux, Python 3.12, uv sync --locked --extra dev, Git 2.43).

• The new tests test_parse_unified_diff_reads_copy_headers (exact and edited copies) and test_attempt_diff_lists_committed_copies_once_with_copy_detection (committed copy in an attempt finalized with diff.renames=copies) fail on main and pass with this change.

• python tests/test_unified_diff_canvas.py and python tests/test_work_artifact_registry.py: passed.

• ruff check server tests/test_unified_diff_canvas.py tests/test_work_artifact_registry.py and git diff --check: passed.

• pytest tests -k "diff or canvas or artifact": 183 passed, 18 skipped. The 6 failures are test_auip_artifact_style.py::test_real_entry_css_delivery_and_advisory_boundaries, which fails the same way on unmodified main in this environment.

• Parsed real git -c diff.renames=copies diff HEAD output (Git 2.54) with an exact copy my src.txt -> my dup.txt. Before: src.txt, my src.txt, my dup.txt (all modified). After: my dup.txt (copied from my src.txt) and my src.txt.

• Relevant Python tests pass

• CPU/model-less baseline remains supported

• Electron npm run build passes when Electron code changed

• Dependency audit passes when dependencies changed

• Before/after screenshots are attached for visible UI changes

• Documentation/examples are updated for changed settings or contracts

Final check

• This PR addresses one coherent problem without unrelated cleanup
• It does not add a speculative API, fallback, or compatibility path
• No secrets, local state, model weights, voice material, or restricted assets are included
• Third-party notices and provenance are preserved

[Lucas1479]

Thank you for the focused copy-header fix and regression coverage. I verified that copied entries use the existing free-text status field and render without a new consumer contract. The branch is now updated with #290; both sides of the test conflict were preserved and their test bodies were checked unchanged. All 65 relevant Windows tests, Ruff and diff checks pass on this head. Existing C-quoted path decoding is a separate non-blocking follow-up; no duplicate rename-only restriction is needed. Merge will wait for hosted CI on the updated head.