Harden hosted MCP runner web-auth flows

[JaeLeex]

Summary

• Derive view-only runner context from trusted web-auth/account headers for hosted MCP reads.
• Let hedge proposal and dry-run execution use view-only account state while keeping real execution behind signing context.
• Add built-in CFI projection fallback for hedge backtests and structured MCP tool errors.
• Add repeatable MCP workload experiment harness with cleanup support.

Test plan

• python3 -m pytest tests/test_mcp_gateway_context.py tests/test_entrypoint.py
• python3 -m py_compile cli/mcp_server.py cli/commands/hedge.py scripts/entrypoint.py scripts/mcp_workload_experiment.py
• Production smoke confirmed setup/account/backtest health and structured runner errors.

Made with Cursor

[sdb001]

Local review on this PR: the focused checks pass and I did not find a direct blocker in the agent-cli changes.

Checks run:

• python3 -m py_compile cli/mcp_server.py cli/commands/hedge.py scripts/entrypoint.py scripts/mcp_workload_experiment.py
• .venv312-review/bin/python -m pytest tests/test_mcp_gateway_context.py tests/test_entrypoint.py = 29 passed

I would hold merge until Nunchi-trade/web-auth#67 narrows the INTERNAL_MCP_EXPERIMENT_TOKEN auth scope. This runner flow depends on the web-auth trusted context boundary, and #67 currently accepts that internal token through shared user-scoped auth middleware.

[sdb001]

Rechecked after the web-auth auth-scope fix in Nunchi-trade/web-auth#67. I’m comfortable approving this runner PR now.

The focused checks had already passed locally:

• python3 -m py_compile cli/mcp_server.py cli/commands/hedge.py scripts/entrypoint.py scripts/mcp_workload_experiment.py
• .venv312-review/bin/python -m pytest tests/test_mcp_gateway_context.py tests/test_entrypoint.py = 29 passed

Merge order note: this should still land after the fixed web-auth#67 layer, since it depends on that trusted context boundary.