fix: preserve PostgreSQL columns for partial execution timing

[Bortlesboat]

Overview

PostgreSQL uploads retain the expected columns when a snapshot or test result lacks a compile or execute timing stage. Each missing timestamp becomes SQL NULL, so partial or empty timing lists no longer produce malformed VALUES tuples.

Update type - breaking / non-breaking

• Minor bug fix
• Documentation improvements
• Quality of Life improvements
• New features (non-breaking change)
• New features (breaking change)
• Other (non-breaking change)
• Other (breaking change)
• Release preparation

What does this solve?

Fixes #573. Fixes #574.

The PostgreSQL regression covers complete, compile-only, execute-only, empty, unrelated and reversed timing lists for both upload paths, checking tuple arity and subsequent fields. It failed before the fix; the full integration build passed 50 nodes afterward, with zero errors and two no-ops. An independent rerun also passed.

Outstanding questions

Other warehouse execution was not repeated. The new regression is PostgreSQL-only; the adapter gating was checked for the other six adapter names.

What databases have you tested with?

• PostgreSQL 15.19
• Snowflake
• Google BigQuery
• Databricks
• Spark
• N/A