Repair main channel package for 2026.04.06.04

[alexphillips-dev]

What changed

• rebuild the 2026.04.06.04 package for the main channel
• update folderview.plus.plg to use main branch manifest and archive URLs
• replace the checked-in 2026.04.06.04 archive and checksum with the rebuilt stable-channel artifact

Why

The earlier dev -> main merge carried the 2026.04.06.04 artifact set from dev, so main failed both guard-suite and Release On Main with a branch-channel mismatch.
The concrete failure was:
pluginURL branch mismatch. expected=https://raw.githubusercontent.com/&github;/main/folderview.plus.plg, found=https://raw.githubusercontent.com/&github;/dev/folderview.plus.plg

A manifest-only flip would unblock the guard, but the deterministic build check showed the checked-in archive itself was still the dev-channel build. This PR repairs the full stable-channel package state.

Validation

• bash scripts/release_guard.sh
• bash scripts/run_ci_suite.sh --lane guards
• bash scripts/run_ci_suite.sh --release
• pre-push hook suite passed