Phase 2: Separate LIB and EVM Send confirmations

[dnlbui]

What Changed

EVM transfers now use a dedicated confirmation modal with their own network, fee, signing notice, and USD estimate elements.

• Remove shared LIB DOM replacement, visibility restoration, and event interception. Share styles through scoped selectors without changing the LIB markup.
• Render the EVM transaction snapshot before showing confirmation.
• Keep approval settlement consistent across Confirm, Cancel, close, Back, and dismissal; reject overlapping approvals.

Fixed Flow

Review an EVM transfer from its Send form: confirmation shows the selected asset, recipient, network, and native fee immediately. Cancel or close returns without approving the transfer. LIB confirmation retains its own fields and behavior.

Why

Separate confirmation ownership prevents EVM rendering and dismissal handlers from modifying LIB confirmation state.

Validation

Local tests remain ignored and are not included in this PR.

• JavaScript syntax checks for app.js and evm-assets.js; git diff --check.
• node tests/lib-evm-modal-separation.browser.test.mjs --phase=2.
• node tests/evm-send-fee-usd.browser.test.mjs.
• Local Node regressions passed for fee/USD estimates, modal transitions, and contextual transfers.

Browser checks cover native/ERC20 assets, missing prices, small fees, cancellation, notes, duplicate warnings, and desktop/mobile layouts using simulated preparation. No funded transfer was broadcast.

Stack

Phase 2 of four phases; depends on phase 1. Its base is codex/1748-phase-1-send, so this diff contains only confirmation changes. Merge phase 1 first, then retarget this PR to main.

Refs #1748