Secure cell protocol salvage and hygiene cleanup

[ramtamilselvan]

Summary

• salvage the useful secure cell, trust-kernel, federation, and finance protocol surfaces from the stale DX branch onto clean main
• restore the missing prerequisite trust packages needed for the salvaged line to compile and test cleanly
• remove tracked Go build cache residue and normalize the commit series into professional subsystem-first history
• reconcile branch drift with the current PoUW and Nitro runtime contracts

Validation

• go test ./app ./pkg/... ./x/pouw/...
• cargo check -p aethelred-core
• git fsck --connectivity-only --no-dangling

Notes

• this branch is a cleaned salvage of the old ramesh/dx-overhaul-20260408 work, not a direct merge of that stale branch
• commit authorship is normalized to Ramesh Tamilselvan <rameshtamilselvan@gmail.com>
• forbidden tracked-content and commit-message scan for assistant or bot branding is clean