Fix #3403: wrap top-level infix queries decoding into case classes - #3404

Fixes #3403.

Problem

#3147 (c334986f, released in quill-engine 4.8.6) made top-level infix queries pass through unwrapped (TopInfixQuery). For case-class results this silently changes the decode contract: extractors decode positionally in field-declaration order, while the raw SQL — e.g. SELECT b.* FROM blocked_periods b — returns the table's physical column order (including columns appended by later ALTERs). When the orders differ, decoders read neighboring columns' values: exceptions if types/enum members mismatch, silently wrong data if they don't.

Reproduction

Any table whose DDL column order differs from the case class:

CREATE TABLE blocked_periods (id UUID, home_id UUID, period DATERANGE, reason VARCHAR, active BOOLEAN);
ALTER TABLE blocked_periods ADD COLUMN source VARCHAR;          -- appended later
ALTER TABLE blocked_periods ADD COLUMN occupancy_status VARCHAR; -- appended later

case class BlockedPeriod(id: UUID, homeId: UUID, period: DateRange, reason: String,
                         source: BlockedPeriodSource /* enum */, occupancyStatus: OccupancyStatus /* enum */, ...)

run(quote { sql"""SELECT b.* FROM blocked_periods b WHERE ...""".as[Query[BlockedPeriod]] })
// 4.8.5: SELECT x.id, x.home_id, ... FROM (SELECT b.* ...) AS x  -> correct
// 4.8.6: SELECT b.* ...                                          -> source decoder reads occupancy_status:
// NoSuchElementException: OCCUPIED is not a member of Enum(BOOKING, ...)

The new SqlQuerySpec cases in this PR encode the contract at the SQL level (sql"SELECT * FROM TestEntity".as[Query[TestEntity]] must stay wrapped).

Fix

Raw passthrough remains for single values (one column) and tuples (column order is explicit in the same expression — the #3147 use case). Case-class results keep the wrapping query, whose explicit projection pins column order — the pre-4.8.6 behavior.

Validation

• SqlQuerySpec: 92/92, including the existing Improve handling of raw-queries #3147 tuple/value passthrough tests (unchanged) and the two new case-class tests.
• Production reproducer (200+ module Scala 3 codebase, Postgres testcontainers): the failing spec above goes red → green with only this engine change applied; the affected service's full persistence suite passes (71/71).

Single-commit bisection that identified #3147 is documented in #3403.