feat(console): bundle Ink frontend in releases; default to it when Node present

[Fullstop000]

What

Make the Ink frontend the default UI for installed/upgraded ignis (when Node ≥18 is present), by bundling it into releases. Follow-up to #174, which left Ink opt-in and the JS packaging deferred.

How

• release.yml — npm ci --omit=dev per runner (ink+react: portable base64-WASM yoga, no native addons), bundles ignis-tui/{src,package.json,package-lock.json,node_modules} into every platform archive.
• install.sh / ignis upgrade — lay the bundle down at ~/.ignis/ignis-tui. Upgrade does it before swapping the binary (failure ⇒ old install intact) and fully replaces the tree, keeping JS + binary in lockstep.
• locate_ink_entry — resolves an explicit IGNIS_TUI_ENTRY, then a source-checkout ignis-tui/ above the binary, then ~/.ignis/ignis-tui. An entry only counts when a sibling node_modules exists, so a checkout without npm install stays on ratatui instead of crashing on a missing import.
• IGNIS_FRONTEND=native forces the built-in TUI; any failure (Node missing, deps absent) falls back to it.

Tests

• New unit coverage: locate_ink_entry order + the node_modules-required rule; install_frontend_into full-replace + no-op-without-bundle.
• The two native-TUI e2e suites pin IGNIS_FRONTEND=native (a dev with Ink deps installed would otherwise auto-launch Ink and fail them).

Verified locally

• Full workspace test green; clippy + fmt clean; --locked release build OK.
• npm ci --omit=dev resolves prod deps (ink+react import OK), devDep excluded.
• End-to-end: binary in an isolated dir + bundle at a fake ~/.ignis/ignis-tui → launches Ink (screenshot-confirmed).

Caveats

• The actual cross-platform release.yml packaging only runs on a tag push — verified its commands locally, not the CI job itself.
• First upgrade is chicken-and-egg: v0.39.0 ships no JS bundle and its upgrade.rs doesn't lay JS down, so the first ignis upgrade to this version swaps only the binary → still ratatui. Re-run the install.sh curl one-liner to get Ink; from this version's binary onward ignis upgrade maintains it.

Checklist

• cargo fmt --all -- --check
• cargo clippy --workspace --all-targets -- -D warnings
• cargo test --workspace
• cargo build --release --locked
• secret scan clean