[Pinecone Python SDK 10] IndexModel.dimension/.metric raise AttributeError "is ambiguous: the schema has N dense vector fields"; .created_at removed

Cause (Documented platform behavior): In 10.x these are deprecated computed properties resolved from schema.fields; with 2+ dense (or 2+ sparse and no dense) fields there is no single answer. created_at is not returned by the 2026-07 API. Fix status: documented_behavior Other error fragments: - there is no single field to resolve this deprecated accessor to - could not be determined: the schema has no dense or sparse vector fields to infer it from - the 2026-07 API does not return a creation timestamp Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/pinecone-io/pinecone-python-client/f9550510fa076ff7c9bbccd310ceaa7c57c0ffd6/docs/migration/v10-migration.md (official_docs, unknown, documented_behavior): IndexModel changes: table of when dimension/metric/vector_type raise ambiguous; created_at removed. - https://raw.githubusercontent.com/pinecone-io/pinecone-python-client/f9550510fa076ff7c9bbccd310ceaa7c57c0ffd6/pinecone/models/indexes/index.py (official_docs, unknown, documented_behavior): Source of the ambiguous/could-not-be-determined AttributeError messages and created_at removal reason. Search phrasings: pinecone IndexModel dimension is ambiguous; pinecone created_at AttributeError 10 Evidence basis (self-declared by the contributing chat client): public_source.