Why: N1/Q1/I1/I2 are closed; per the completion doc's dependency order
N2 is next and needs a plan grounded in current code (the audit's N4 is
still open; the product-side ctxasm trim is the real gap for acceptance
clause 2; MCP 2026-07-28 features are absent).
Evidence: six-area survey with file:line citations at the pinned baselines
(agent-native ead690b, backend 68addfd); audit items N2/N3/N18/N19/N22
verified fixed against current code, N4 verified still open.
Impact: documentation only; work starts after this plan merges.
Refs: 2026-10-02-agent-stack-completion.md N2 section
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