Motivation

gog already implements row/column add/delete and cell merge via the gog docs sed brace DSL (|2|[+1,0]/foo/, |2|[1,1:1,3]/merge/, etc.). These are powerful but the syntax overhead is high for one-shot calls in scripts. A user who knows "I want to add a row at the end of the second table" should not have to learn the regex address syntax.

The implementation already exists in internal/cmd/docs_sed_table_ops.go (InsertTableRow / DeleteTableRow / InsertTableColumn / DeleteTableColumn / MergeTableCells / UnmergeTableCells emitted from the sed path). Lifting them into top-level commands is mostly a CLI surface change.

Repro

# Today (works but unwieldy):
gog docs sed <DOC_ID> '|2|[+1,0]//'                  # append empty row to 2nd table
gog docs sed <DOC_ID> '|2|[1,1:1,3]/merge/'           # merge top row cols 1-3

# Wanted:
gog docs table-row insert <DOC_ID> --table=2 --at=end
gog docs table-merge <DOC_ID> --table=2 --range=1,1:1,3

Proposed surface

gog docs table-row insert <docId> --table=<idx|header-text> --at=<n|end> [--values-json=...]
gog docs table-row delete <docId> --table=<idx|header-text> --row=N
gog docs table-column insert <docId> --table=<idx|header-text> --at=<n|end>
gog docs table-column delete <docId> --table=<idx|header-text> --col=N
gog docs table-merge <docId> --table=<idx|header-text> --range=r1,c1:r2,c2
gog docs table-unmerge <docId> --table=<idx|header-text> --cell=r,c

--table=<header-text> mode: resolves to the table whose first-row-first-cell text matches verbatim (Docs API has no native "table label" — this is the most stable proxy in practice).

All commands map to single batchUpdate requests; the brace-DSL implementation can be lifted into a shared helper.

Acceptance criteria

• 1:1 behavioural parity with the corresponding sed brace expressions.
• --table=<header-text> resolves the table by verbatim first-cell text; ambiguity errors out.
• Index-based --table=N matches the sed convention (1-based, negative from end, * for all).
• Returns the index of the new row/column or the merged range in JSON mode.

References

• InsertTableRowRequest / DeleteTableRowRequest / InsertTableColumnRequest / DeleteTableColumnRequest: https://developers.google.com/workspace/docs/api/reference/rest/v1/documents/request
• MergeTableCellsRequest / UnmergeTableCellsRequest: same page
• Existing brace-DSL implementation: internal/cmd/docs_sed_table_ops.go