feat(nodes): show the configured stream transport

[Zakkaus]

Problem

Nodes show only the proxy protocol, so users cannot identify a configured XHTTP transport even when the backend reports it.

How I fixed it

Display the optional configured transport beside the protocol, preserving the existing display for absent or null fields and the existing protocol filter. Keep unfamiliar transport names readable. Add three-language help, an XHTTP demo node and tests that preserve raw xhttp/splithttp links through create and edit. Net lines: application code +9, generated types +8, unit tests +33, e2e +33, CSS 0; locale replacements have zero net lines. The owner approved the local preview.

Verified

pnpm check passes on the rebased branch. Coverage, build and size checks passed before the rebase, whose only base change is release tooling. Chromium completed 1,818 cases with 14 skipped; two added cases initially failed because the mock source needed a refresh, and the three affected cases passed after the correction. WebKit passed 319 with 18 skipped. check:gen verifies the updated contract, and the implementation had an independent cold review. CI reruns the full gates on this branch. Backend transport reporting is a separate honk change; older backends retain the existing display.

Submitted and answered for by (Human responsible, GitHub username): Zakkaus

• I understand this change and will answer for every line. An AI cannot answer for me.
• This branch is based on the current main.
• Each commit contains one coherent change with an English type(scope): subject and a short English body.
• I ran the applicable CI gates in CONTRIBUTING.md; the Verified section records the commands, results and any checks I could not complete.
• I updated the strings in en.json and in every complete language's catalogue when I changed interface text.
• I attached light and dark screenshots when I changed the interface appearance.
• I ran pnpm gen:api and pnpm check:gen when I changed the API contract.
• I checked the boxes above without reading them.
• I am an AI agent, and this content was submitted without human review.