feat(rpkg): return event state as data.frame or list-of-data.frames

[CGMossa]

Stacked on #192. The R bindings flattened Success / Error rows into a single data.frame with NA-padded columns between variants — useful for nothing. With miniextendr's new vec_to_dataframe_split, callers now get a bare data.frame when only one variant occurred, or a named list(Success = <df>, Error = <df>) when both occurred, each carrying only its own columns. For dvs_add / dvs_get, when there's no glob, the rpkg now bypasses resolve_paths_for_* and lets validate_for_* (with #192's cwd-relative support) classify each path per-row, so missing / untracked paths surface as Error rows instead of bailing the whole call. ui/main_events.sh walks the 12 cases ({all-success, all-failure, mixed-success, mixed-failure} × {add, get, status}) so reviewers can eyeball the shape switch.

AI-written details

Summary

• Bumps the miniextendr pin so vec_to_dataframe_split is available.
• Adds per-command Serialize view enums (AddResultView, GetResultView, FileStatusSuccessView / ErrorView), externally tagged so the splitter sees Success / Error as proper variants.
• dvs_status partitions manually so the Success data.frame carries add_time as a POSIXct column (jiff timestamps go directly to OffsetDateTime, not through serde's RFC 3339 string form).
• R-side .dvs_finalize helper recursively applies new_dvs_bytes to byte columns and tibble::as_tibble, preserving whichever shape Rust returned.
• For dvs_add / dvs_get: when no glob is supplied, bypasses resolve_paths_for_* and feeds user paths straight to add_files / get_files. validate_for_add / validate_for_get already classify each path per-row (Valid / NotFound / OutsideProject / IsDirectory for add; Tracked / NotTracked / NotFound for get) and the per-row machinery surfaces non-Valid statuses as Error rows. resolve_paths_for_* stays for the directory-walk + glob case.

Test plan

• cargo check -p dvs-rpkg clean
• devtools::test('dvs-rpkg') passes (test-add.R / test-get.R updated to assert per-row Error rows for missing / untracked paths instead of expect_error)
• bash ui/main_events.sh exercises 12 cases ({all-success, all-failure, mixed-success, mixed-failure} × {add, get, status}) and prints class and shape per case. Verify bare tibble for all-success/all-failure, named list(Error, Success) for mixed cases.

Notes

• Depends on fix(paths): handle cwd-relative input in validate_for_add / validate_for_get #192 (fix(paths): handle cwd-relative input in validate_for_add / validate_for_get). The bypass-resolve_paths_*-when-no-glob change relies on validate_for_* doing its own cwd-to-repo-relative conversion.
• Until fix(paths): handle cwd-relative input in validate_for_add / validate_for_get #192 lands, local testing needs an uncommitted [patch."https://github.com/A2-ai/dvs2"] dvs = { path = "../../../dvs" } block in dvs-rpkg/src/rust/Cargo.toml. After fix(paths): handle cwd-relative input in validate_for_add / validate_for_get #192 merges, rebase onto main and run just rpkg-update -p dvs to bump the rpkg's dvs pin to the new main SHA.

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Drafted by Claude (claude-opus-4-7). Reviewed by the author.