assurance: bind closed formal scope and isolate release airgap

[attractor-set]

Hardens Alpha4 Runtime assurance with closed canonical formal/proof scope binding, structural validator independence, and isolated release-artifact verification.

Verified:

• 34/34 tests PASS
• relational canonical scope 1/1 PASS
• formal-reflection canonical scope 1/1 PASS
• proof canonical scopes 2/2 PASS
• relational source derivations 8/8 PASS
• validator independence 28/28 PASS
• TLAPS 22/22 PASS
• local triangulation 2420/2420 PASS
• release air-gap structural 7260/7260 PASS
• identity sensitivity 5/5 PASS
• air-gap grand total 7265/7265 PASS
• companion runtime isolation PASS
• post-build TLAPS PASS
• release admission certificate PASS
• public release audit PASS
• Alpha4 Runtime release gate PASS
• formal semantic delta NONE

Pinned Seed:
0028f1d25a4f1d052a9b998baf402898446ac599

Commit:
1a27335