Add a `--vastai` acceptance scenario to mvp-chat-check that provisions real VastAI nodes and verifies the remote provider data path, and standardize the VastAI API key on VAST_API_KEY.
- xtask: add the VastAi variant and `--vastai` flag to the mvp-chat-check scenario, passing `--vastai --yes --endpoint-addr-mask relay-only` (no --cached-model) and gating it on a new require_vastai_network_facts check (node_spec workers, ProvisionStart, provider_start, iroh_driver ready).
- xtask: track VastAI dump-log facts (vastai_node_spec_worker_count, vastai_provision_start_nodes, vastai_provider_start_nodes) via record_vastai_provision_dump_log_event and skip the local ChatProgress span assertion for the remote scenario.
- config: rename the VastAI key env var to VAST_API_KEY in ResolvedVastAiConfig validation while keeping MVP_VASTAI_API_KEY/VASTAI_API_KEY fallbacks.
- orchestrator_app: resolve the api key with VAST_API_KEY first, then MVP_VASTAI_API_KEY/VASTAI_API_KEY, and update the missing-key error messages.
Signed-off-by: Zachery Aaron Shores-Chmielewski <zacheryasc@gmail.com>
Zachery Aaron Shores-Chmielewski
c526e929c3