7b97786ab7
Closes B2 (rebuild-table reused outside relationships) and
C2 (full add/drop/rename/change-type column operations).
* drop column [from] [table] <T>: <col>
- ALTER TABLE DROP COLUMN (SQLite 3.35+) + metadata
cleanup in __rdbms_playground_columns.
- Refuses PK columns and columns involved in a declared
relationship (drop the relationship first).
* rename column [in] [table] <T>: <old> to <new>
- ALTER TABLE RENAME COLUMN (SQLite 3.25+); SQLite
cascades the rename through FK declarations on other
tables.
- Mirrors the new name into both metadata tables
(__rdbms_playground_columns, __rdbms_playground_relationships)
so describes stay accurate after a rename.
- Refuses identity rename and name collisions.
* change column [in] [table] <T>: <col> (<newtype>)
- Routes through the rebuild_table primitive (ADR-0013)
since SQLite ALTER doesn't support type changes.
INSERT INTO new SELECT FROM old; STRICT typing enforces
cell compatibility, transaction rolls back on mismatch.
- Refuses PK columns, relationship-involved columns,
`serial` target, and no-op same-type changes.
Adds 20 tests (parser + db layer); updates the in-app help
listing. Both prepositions independently optional in each
new command, matching `add column`'s grammar shape.
Total: 449 passing, 0 failing, 0 skipped (up from 429).
Clippy clean.
Known spec gap: column-type-change conversion compatibility
is not yet documented (currently relies on SQLite STRICT
errors); follow-up will close this.