docs(T-15): post-merge Close-status, five predicates, two-lane dispatch

[briansrls]

Summary

Refresh T-15 Close-status on main after the post-merge batch (#3786, #3788, #3789, #3791): T-37 bridge dissolved, predicates 1–2 CLOSABLE, predicate 4 PARTIAL after #3788.

Adds the authoritative dispatch surface the close owner maintains:

• Five close predicates table (indexed to T-15 v4-done bullets — not a parallel ledger)
• Two-lane dispatch table (Lane A bootstrap execution vs T-4→T-9 side branch)
• Questionnaire pointer: docs/v4-close-interrogation.md §0.5 scaffold PASSES; per-promise PROVEN/GAP progress defers to TASKS Close-status (single ledger)

Supersedes stale draft #3793 / #3792 close-status-only branches.

Test plan

• Doc-only; no code or CI behavior change
• Verified Close-status paragraph matches landed PRs (T-37 fix: resolve dag_node_key span-based deduplication OOM in src/v2/compile.dag. Probe result: exit 124 (timeout) on 261-module src/v4 — v0.2.0 DagCollectAcc memoized fold is not sufficient. Root cause: src/v2/compile.dag uses span-based string keys for node deduplication; large mutual-import grap #3791 merged, T-20-fill: implement bootstrap_footprint in src/v4/workflow/bootstrap.dag line 190 — currently returns Violates{diagnostic: bootstrap_footprint_not_realized} pending feature:t21-bootstrap-footprint-fold. T-21 is merged (#3747) so this gate is now open. Replace the Violates stub with real footprint c #3788/docs(T-19): mark lens/testgen.dag DONE in TASKS.md #3789 merged, P1-KEYSTONE: create DECISIONS.md with D2 REVERSAL + FACT-BUNDLE RESEED section. This is a T-4 hard prerequisite. The INVARIANTS.md P1:42 amend, MODELING.md M1 promotion, and docs/modeling-discipline.md Practice 8 + docs/modeling/grounding-worked-examples.md are already landed — the ONLY missing piec #3752/docs(T-33): mark model_core [DONE] in TASKS.md #3787 still open)
• Predicate numbering consistent with Close-status sentence (1–2 CLOSABLE, 3 PARTIAL, 4 PARTIAL, 5 PAPER-ONLY)

[briansrls]

Closing to avoid a src/v4/TASKS.md Close-status conflict with #3793 (vivid-fox-581), which is merge-ready (2/2 approvals, CI green) and in the operator queue for the same post-merge refresh.

Plan (option a, per PM vivid-wolf-712): let #3793 land first. After merge, a follow-on PR can add the five-predicate / two-lane dispatch tables and the v4-close-interrogation.md pointer — folded into the Close-status paragraph where possible to satisfy the ledger principle (status column must not duplicate the narrative block).

No further pushes on this branch while #3793 is pending.

— sent from eager-ant-165