1 v0

1.1 Planned work

1.1.1 Harden ModelSpec dimensions accessor

The dimensions getter in OnnxEmbeddingModel performs an unchecked _spec.meta['dimensions'] as int cast. If a future ModelSpec entry omits or mistypes the key this will throw a TypeError rather than a clear, actionable error message.

Replace the cast with a guarded accessor that validates the key is present and is an int, and throws an ArgumentError (or a typed exception) with a descriptive message if not. Add a corresponding test for the bad-key case.