fix: qualify struct field access to avoid binder ambiguity post-join

[shriram-devrev]

Summary

When a dimension SQL references a struct field like stage.stage_id, the aliaser previously skipped it because column_names.length !== 1. After joining tables that expose a column with the same name as the struct root (e.g. devusers.stage alongside issue.stage), DuckDB's binder fails with:

Binder Error: Ambiguous reference to column name "stage" (use: "issue.stage" or "devusers.stage")

The query can't even run because the bare `stage` resolves to two different columns in scope.

What changed

Make the aliaser schema-aware:

• Introspect each table's physical columns via `DESCRIBE (<tableSchema.sql>)` in both the browser and node wrappers before running the batch.
• Derive `knownTableNames` from the current schema batch.
• Rewrite a multi-part column ref as `..<rest...>` only when the leading identifier is a known column on the current table.
• Leave cross-table references (`customers.id`), already-qualified refs, lambda-bound identifiers, and unknown multi-part refs untouched.
• Fall back to the legacy length-1 behavior when schema information is not supplied, preserving backwards compatibility.

Decision matrix

Case	`tableName`	Column set	Known tables	Result
`stage.stage_id` (struct)	`issue`	has `stage`	—	`issue.stage.stage_id` ✓
`customers.id` (foreign alias)	`orders`	no `customers`	has `customers`	unchanged ✓
`issue.id` (already qualified)	`issue`	—	—	unchanged ✓
`foo.bar` (unknown)	`issue`	no `foo`	no `foo`	unchanged (fail-safe) ✓
`x -> x.field` (lambda)	any	—	—	unchanged ✓

Files touched

• `meerkat-core/src/utils/ensure-sql-expression-column-alias.ts` — schema-aware decision logic
• `meerkat-core/src/utils/ensure-table-schema-alias-sql.ts` — plumbs `tableColumnsByName` and `knownTableNames` into context
• `meerkat-browser/src/ensure-table-schema-alias/ensure-table-schema-alias.ts` — `DESCRIBE` introspection
• `meerkat-node/src/ensure-table-schema-alias/ensure-table-schema-alias.ts` — `DESCRIBE` introspection
• Fixtures + specs updated

Test plan

• `npx jest meerkat-core/src/utils/ensure-sql-expression-column-alias.spec.ts` — 29 passed (7 new)
• `npx jest ensure-table-schema-alias` — 9 passed (1 new)
• `npx nx test meerkat-node` — 887 passed
• `npx nx run-many -t test -p meerkat-core,meerkat-browser` — 515 passed
• Verify end-to-end in devrev-web: issue dashboard grouping by `priority_uenum` with `devusers` join no longer hits the binder error

[github-actions]

⚠️ Heads-up: This repository will be blocked from any work other than patching.

File meerkat-browser/src/ensure-table-schema-alias/ensure-table-schema-alias.ts is not allowed to be modified in this patch.
The following vulnerability issues are past SLA:

• ISS-285092, overdue 5.0d, sev high, owner: ayush.pandya@devrev.ai, checked: 2026-04-22 09:17 UTC

Note that there is significant latency in updating this list. Please reach out on #antifragile if you are in a hurry or have an emergency.

[github-actions]

⚠️ Heads-up: This repository will be blocked from any work other than patching.

File meerkat-browser/src/ensure-table-schema-alias/ensure-table-schema-alias.spec.ts is not allowed to be modified in this patch.
The following vulnerability issues are past SLA:

• ISS-285092, overdue 5.0d, sev high, owner: ayush.pandya@devrev.ai, checked: 2026-04-22 10:22 UTC

Note that there is significant latency in updating this list. Please reach out on #antifragile if you are in a hurry or have an emergency.

[github-actions]

⚠️ Heads-up: This repository will be blocked from any work other than patching.

File meerkat-browser/src/ensure-table-schema-alias/ensure-table-schema-alias.spec.ts is not allowed to be modified in this patch.
The following vulnerability issues are past SLA:

• ISS-285092, overdue 5.0d, sev high, owner: ayush.pandya@devrev.ai, checked: 2026-04-22 10:55 UTC

Note that there is significant latency in updating this list. Please reach out on #antifragile if you are in a hurry or have an emergency.