[kvlonge]

Why

The native schema validator reports valid Snowflake output aliases as unknown or ambiguous when they are reused later in the SELECT, in its WHERE clause, or in ORDER BY.

Changes

• accept an unknown Snowflake name only when AST evidence proves it references an earlier output alias in the same SELECT or an output alias in that SELECT's WHERE
• accept an ambiguous ORDER BY name only when AST evidence proves the same SELECT declares that output alias
• retain findings for forward references, unrelated unknown names, other clauses, quoted names, and other dialects

Verification

• focused schema-validation tests after rebasing over the VALUES compatibility fix: 14 passed
• Ruff and Ty checks passed for touched files
• Fensu passed
• uv sync --all-extras
• make check-ci after conflict resolution
• public-repository hygiene scan
• cache-free static compile of the downstream 974-model project with the three affected alias boundaries and the adjacent VALUES boundary enabled together: 0 errors, 0 warnings