Add entity context for Codex memory saves

[ishaanxgupta]

What changed

• Added Codex-specific user and project entityContext prompts.
• Forwarded optional entityContext through SupermemoryClient.addMemory().
• Sent user context during automatic transcript capture.
• Sent project context from the explicit supermemory-save skill, with custom-container context derived from the configured container description when --container is used.
• Documented the behavior and added regression coverage for the wiring.

Why

Claude Supermemory already sends entity-specific context on write calls, which lets Supermemory persist extraction guidance on the container tag. Codex was creating/saving to tags without that field, so container tags could show no entity context and extraction had less guidance.

[MaheshtheDev]

what about results? any improvements?