fix(reader_base): bind TextQuery args correctly instead of passing dal.QueryArg itself

[trakhimenok]

Summary

• dal.NewTextQuery accepts dal.QueryArg{Name, Value} values, but getReaderBase's dal.TextQuery branch passed each arg struct straight through as a[i] = arg — database/sql has no idea how to convert a dal.QueryArg into a bind value, so any TextQuery with a non-empty Args() failed outright: sql: converting argument $1 type: unsupported type dal.QueryArg, a struct. Named @param/:param/$param placeholders in native SQL could never bind at all. Found via datatug-cli PR #206's body (item 2) — its pkg/secureread.RunNativeSQL currently works around this by binding placeholders itself before ever reaching this adapter.
• Fix: a named arg (Name != "") becomes a sql.NamedArg via sql.Named, so an @name-style placeholder binds by name; a positional arg (Name == "") passes its Value straight through for ordinary ?/$N placeholders.

Checked for duplicate work first

Per instructions, checked whether the pushed layered-acl-query branch (codex layered-ACL work) already fixes this before doing anything:

git fetch origin layered-acl-query
git diff origin/main..origin/layered-acl-query -- reader_base.go

It only changes reader_base.go's dal.StructuredQuery branch (adds dialect-aware compileStructuredSQL for SQLite), leaving the dal.TextQuery branch — the one this bug lives in — completely untouched. No overlap, nothing duplicated; proceeded with the fix.

Reproduction

Three new tests, run against a real in-memory SQLite database (modernc.org/sqlite, not a mock, matching this repo's own openTestSQLiteDB helper) — positional-only, named-only, and mixed positional+named in the same query:

• TestGetReaderBase_TextQuery_PositionalArgs
• TestGetReaderBase_TextQuery_NamedArgs
• TestGetReaderBase_TextQuery_MixedArgs

Confirmed all three fail with the exact error above against the unfixed code (go test -run TestGetReaderBase_TextQuery -v before the fix), then pass cleanly after the one-line fix.

Validation

• wb run -- go build ./... — clean.
• wb run -- go vet ./... — clean.
• wb run -- go test ./... — clean, full suite green, including the three new tests.
• wb run -- go test ./... -run TestConformance -v — the shared dalgotest.RunConformance suite (17 subtests) stays fully green.
• gofmt -l . — clean, no output.

go mod tidy -diff reports a large, pre-existing go.sum cleanup (stale versions of dal-go/dalgo, dal-go/record, modernc.org/sqlite, etc. left over from past bumps) — unrelated to this fix and out of scope for a narrow bug fix, not touched here.

Do not merge — landing is owned by a separate session. (Note: dalgo repos auto-tag on main — no hand-tagging done or needed here.)

🤖 Generated with Claude Code

https://claude.ai/code/session_01Dd3aoE41JSShyUuUmW8sSi