fix: make Toccata covenant lifecycle transactions deployable

[w00c00]

Summary

• Enforce a conservative 0.5 KAS/TKAS Studio covenant-cell floor and select the lowest-mass eligible funding UTXO.
• Build Toccata v1 inputs with computeBudget and zero legacy sigOpCount.
• Calculate lifecycle fees after full redeem-program assembly, consume pinned engine fee/mass data, and reserve final CheckSig execution cost.
• Keep phrase-free TN10 inheritance renewal bound to the exact current same-covenant continuation with a 0.02 TKAS cap.
• Bump Studio to v0.2.7 and add bilingual release notes with live TN10 evidence.

Verification

• npm run verify: 42/42 tests and production build passed.
• cargo test: 2/2 tests passed.
• cargo clippy --all-targets -- -D warnings: passed.
• npm audit: 0 vulnerabilities.
• cargo audit: no vulnerability failures; 17 known upstream GTK/Tauri maintenance or unsoundness warnings remain.
• macOS arm64 DMG built with release signing settings; strict codesign, V8 JIT, packaged health endpoint, and all 8 packaged templates passed.
• Live TN10 wallet transfer, 0.5 TKAS covenant genesis, mature 50/50 inheritance distribution, and owner-signed check-in continuation were accepted by a node after local and Kascov preflight.

Live TN10 transactions

• Transfer: f3734e73bd96c0a00437b15298dcc284004af57386786278905a00cd15de53d5
• Covenant genesis: 94d0414ecb2b4c119841bbec5b732e882b82b3713abfca563b32975086aaa656
• Mature inheritance: 185bac653855e7b99f36c7ac0f4b97af4b911ed1a88531ec5a9fb1b6e5ca4fd2
• Signed check-in continuation: 103e9047cdffec4dd41f3b4632b09898fa78547a6d9a54ae0cc3093692adfb28

Mainnet remains disabled by default. SilverScript and the KCC721 pack remain experimental.