`RawBrowseCommitMapper.BuildSqlTagConfig` emitted a WideRow blob carrying only
table + columnName. A wide-row tag must also say WHICH row it reads, so both
`SqlEquipmentTagParser` (the runtime authority) and `SqlTagConfigModel.Validate`
(the authoring gate) refused it — a browse-committed Sql tag was never readable,
first silently as BadNodeIdUnknown and, since #551 put the gate on the import,
loudly at commit.
`SqlBrowseSession` now states a fourth address field: the table's preferred
date/time-typed column, computed from the columns its attributes call ALREADY
read (no extra catalog round-trip). Candidacy is decided by
`ISqlDialect.MapColumnType` reporting `DriverDataType.DateTime` — never by column
name, which would order a wide-row read by a string column that merely looks like
a timestamp. Multiple candidates tie-break on FIRST IN CATALOG ORDER (every
dialect's column SQL orders by ordinal position), so the pick is stable across
calls and servers; it is a visible, editable default the typed editor round-trips.
No candidate (a table with no date/time column) is an operator-actionable refusal,
not an invented selector: the only remaining selector is a whereColumn/whereValue
pair whose value is data, not schema, so `DescribeUncommittableLeaf` refuses that
leaf by name, names the table, and points at the tag editor.
The session and the mapper now agree via `SqlBrowseAddressFields` constants rather
than two independently spelled string literals — a disagreement there is silent,
and is exactly the shape this defect had.
`RawTagConfigGateTests`' Sql leg flips from "records the gap" to "browse-commit
output passes the gate", with the no-candidate case pinned as its own test.
Joseph Doherty
7498d39e5b