Added RAOB metadata capabilities

[mollybsmith-noaa]

This PR hopefully will add the ability to do RAOB metadata without breaking anything else.

[Copilot]

Copilot review overview

🟡 Changes recommended

Critical query and configuration issues, plus an output-compatibility issue, remain unresolved.

Get a fresh assessment by requesting another Copilot review.

Review effort: Lite
Findings: 3 · 1

Open (4)

• Quote docType and subDocType placeholders in the query · New
• Quote metadata query value placeholders · New
• Fallback to the default collection for missing configuration · New
• Omit sentinel levels for non-UPPERAIR models · New

What changed in this PR

Adds RAOB metadata support through collection-aware queries and model-level extraction.

Changes:

• Adds METAR/RAOB collection routing.
• Adds levels metadata and level queries.
• Updates SQL templates, documentation, and tests.

File	Summary
write-to-db.go	Adds levels to model metadata.
vxMetadataUpdater.go	Routes collections and assembles RAOB levels.
template-queries.go	Adds level-query support and substitutions.
sqls/​getModelsWithMetadata.sql	Adds collection and metadata filters.
sqls/​getModelsNoData.sql	Adds collection and dataset filters.
sqls/​getDistinctLevel.sql	Adds distinct RAOB level extraction.
settings.json	Adds collection and RAOB settings.
README.md	Documents RAOB support.
meta_update_test.go	Updates configuration test structures.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[randytpierce]

It looks ok to me, and the tests pass in my workspace. I think this improves things.