[Go SDK] ControlPlaneMemoryBackend ignores caller context cancellation

[santoshkumarradha]

Summary

All HTTP methods in ControlPlaneMemoryBackend use http.NewRequest instead of http.NewRequestWithContext, so a cancelled execution context cannot cancel in-flight memory I/O, causing 15-second hangs on timeout.

Context

control_plane_memory_backend.go at lines 59, 88, 125, and 153 construct HTTP requests without a context. The MemoryBackend interface itself also lacks context.Context parameters. When an agent execution is cancelled (user abort, workflow timeout, health-check failure), the in-flight Set/Get/Delete/List HTTP calls to the control plane will continue running until the 15s http.Client timeout fires. Under load, this means cancelled executions hold HTTP connections and goroutines for up to 15 seconds after they should have been cleaned up.

Scope

In Scope

• Add context.Context as the first parameter to all MemoryBackend interface methods (Set, Get, Delete, List, SetVector, GetVector, etc.).
• Update all interface implementations (InMemoryBackend, ControlPlaneMemoryBackend, any test mocks) to accept and propagate the context.
• Use http.NewRequestWithContext(ctx, ...) in ControlPlaneMemoryBackend for all four HTTP methods.
• Update all callers in the agent SDK to pass the execution context through to memory operations.

Out of Scope

• Changing the HTTP client timeout value — that is a separate tuning concern.
• Implementing retry logic on context cancellation.
• Fixing the deep-copy race in InMemoryBackend — tracked separately in G1.

Files

• sdk/go/agent/memory.go — add ctx context.Context to MemoryBackend interface and InMemoryBackend implementation
• sdk/go/agent/control_plane_memory_backend.go:59,88,125,153 — switch to http.NewRequestWithContext
• sdk/go/agent/agent.go — update callers that invoke memory backend methods to pass execution context
• sdk/go/agent/memory_test.go — add test: cancelling context before Get causes the call to return context.Canceled

Acceptance Criteria

• MemoryBackend interface methods all accept context.Context as first parameter
• ControlPlaneMemoryBackend uses http.NewRequestWithContext for all requests
• Cancelling the context passed to a memory operation causes it to return promptly with context.Canceled or context.DeadlineExceeded
• All existing memory backend tests pass with the updated interface
• Tests pass (go test ./sdk/go/...)
• Linting passes (make lint)

Notes for Contributors

Severity: HIGH

This is an interface-breaking change — all callers and mocks must be updated. Search for MemoryBackend usages across sdk/go/ with grep -r 'MemoryBackend' sdk/go/ to find all sites. The InMemoryBackend can accept the context but ignore it (operations are in-memory and non-blocking); the context parameter is there for interface consistency and future use.