* extract-basic: migrate workflow to llama-cloud v2 SDK
Switch extract-basic to llama-cloud>=2.3.0 and the v2 extract API:
configuration_id replaces extraction_agent_id, ExtractConfig mirrors
ExtractConfiguration (tier/extraction_target/etc), and process_file now
uses client.extract.create + wait_for_completion + get with
expand=["extract_metadata"] and ExtractedData.from_extract_job.
metadata_workflow resolves schemas via client.configurations.retrieve
gated on ExtractV2Parameters.
* extract-basic: update fake server and tests for llama-cloud v2
Rewrite FakeLlamaCloudServer.extract for v2 routes (POST/GET
/api/v2/extract, schema validate/generate, /api/v1/beta/configurations
CRUD) and update split to read categories from the nested
configuration payload. Rewrite test_extract and test_split to the v2
SDK shapes (client.extract.run with inline configuration and
configuration_id; split with configuration={'categories': [...]}).
* extract-basic: split configurations namespace out of extract fake
Move /api/v1/beta/configurations CRUD handlers and StoredConfiguration
state into their own FakeConfigurationsNamespace. FakeExtractNamespace
now takes a FakeConfigurationsNamespace and delegates configuration_id
lookups to it. Server wires both namespaces independently.
Adrian Lyjak