[Task 111 defer] Cross-fn discharge propagation requires shared state — defer to Task 117

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Defers Plan D Task 111 (TLS → packed multi-return for sigil_run_loop). Plan B' carryover #1 stays open with revised closure scope.

Why deferred

Three implementation attempts on PR #50 all failed identically. The bug is architectural, not implementation:

Attempt	Mechanism	Result
4dfdbc7	Cranelift [I64, I64] register-pair multi-return + Rust #[repr(C)] struct { u64, u64 }	10 e2e tests fail (discharge-class shapes)
670f7a1	Out-pointer ABI + Cranelift Variable per-fn last-terminal vars	Same 10 tests fail
5e2686e	Out-pointer ABI + per-fn StackSlot (explicit memory ops)	Same 10 tests fail

Diagnostic eprintln commit 4086307 confirmed the cause. For catch_example_recovers_with_42:

• DISCHARGED bypass: writing (42, tag=2) to out=0x7ffc6c12aac8 (in risky's frame)
• top-level terminal: writing (0, tag=0) to out=0x7ffc6c12ab00 (in user-main's frame)

The OLD TLS achieved cross-fn shared state implicitly because TLS is thread-global. Per-fn / per-call mechanisms scope the (value, tag) to the immediate caller; the discharge is invisible to the enclosing handle expression in a different stack frame. Specifically: risky has UserFnAbi::Sync (body shape mismatch with all three Cps body classifiers), so its discharge writes its own slot, then risky's body continues sequentially (result = 42; result + input = 49) and returns 49 via Sync ABI; user-main's handle exit reads its own untouched slot.

Closure path

1. Recommended: defer to Task 117 first-class-k follow-up. Task 117 modifies the same surface; co-shipping the lift uses whichever ABI Task 117 settles on, informed by Task 117's actual requirements rather than guessed in advance.
2. Alternative: thread *mut TerminalResult through every fn ABI as an extra parameter — own multi-PR architectural slice, comparable scope to Plan B' B.3 TypeExpr::Fn lift. Out of Plan D scope unless explicitly authorized.

Files changed

• PLAN_D_DEVIATIONS.md — adds [DEVIATION Task 111] (53 LOC)
• PLAN_D_PROGRESS.md — Task 111 status flips to deferred with closure-path summary

No code changes. PR #50 (the failed implementation attempts) closes without merge; its four commits are preserved on the plan-d-task-111 branch for the diagnostic record.

Stage 11 next

Task 112 (wrapper-fn-frame composition fix). Stage 11 review checkpoint will close on Task 112 alone since Task 111 deferred.

Test plan

• CI green on ubuntu-24.04 (build + test, cold-checkout) — no code change so should pass cleanly
• CI green on macos-14 (build + test, cold-checkout)