claude@clouddev1
5bb0a147f0
Generalises serial and shortid beyond their previous restricted forms: - `serial` is no longer restricted to single-column PK. Non-PK serial columns get an emitted UNIQUE constraint and use application-side MAX(col)+1 at INSERT time (rowid alias still drives the PK case for free; per ADR-0010 worker-thread serialisation, the read-then-insert sequence is safe). - `shortid` columns auto-fill existing null cells when the column is materialised — `add column T: x (shortid)` on a non-empty table no longer leaves rows in a not-really-valid NULL state. - `int -> serial` joins the type-change matrix as always-clean identity (closes the asymmetry vs `text -> shortid`); other sources are refused with a route-via-int hint. - `change column T: x (serial|shortid)` fills null source cells with sequence / generated values in the same rebuild transaction. Internal infrastructure: - ReadColumn gains `unique: bool`; read_schema detects single- column UNIQUE indexes via pragma_index_list / pragma_index_info; schema_to_ddl emits inline UNIQUE for non-PK columns. - ColumnSchema (persistence) gains `unique: bool` so the flag survives YAML round-trip and rebuild-from-text reconstructs it faithfully — preserves the "serial -> int leaves UNIQUE in place" promise across save/load cycles. - ChangeColumnTypeResult.client_side now carries `auto_filled` + `auto_fill_kind` alongside `transformed` + `lossy`; the app handler renders separate note lines when both apply. - AddColumnResult is a new return type carrying pre-rendered [client-side] note lines for the auto-fill paths. Tests: 519 -> 534 (+15). Clippy clean.