adding WATER detour option for downloading and seeding

[WendelHime]

This PR:

• use the latest lantern-water changes that support a http client for magnet downloader and seeder
• add detour option for using another outbound for downloading and seeding the WASM file

[Copilot]

Pull request overview

This PR updates the WATER outbound’s WASM download + seeding pipeline to use the latest lantern-water APIs and to route HTTP traffic through the Radiance Kindling HTTP client stack.

Changes:

• Update lantern-water dependency to a newer revision that supports injecting an *http.Client for WASM downloading and seeding.
• Introduce a shared http.Client in the WATER outbound, optionally sourcing its transport from radiance/kindling.
• Update Go module dependencies (go.mod/go.sum) to include github.com/getlantern/radiance and related transitive upgrades.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

File	Description
protocol/water/outbound.go	Creates a shared HTTP client (optionally Kindling-backed) and passes it into the WASM downloader and seeder.
go.mod	Bumps lantern-water and adds getlantern/radiance plus refreshed indirect dependencies.
go.sum	Reflects the updated dependency graph for the new module versions.

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[garmr-ulfr]

• it also imports radiance kindling HTTP client and uses it for downloading WASM files and seeding

Since radiance depends on lantern-box, lantern-box shouldn't also depend on radiance. Introducing that circular dependency makes it very fragile—changes to radiance now have the potential to break a dependency, or lantern-box would have to use an older version. This makes it very difficult to maintain.

[garmr-ulfr]

LGTM! Just the one comment.