id(serve): world_names_are_bounded_and_are_a_single_path_segment test fails on clean main #1709

Problem

commands::serve::tests::world_names_are_bounded_and_are_a_single_path_segment fails on clean main.

Evidence (2026-10-28, queue worker lane C, task 1853 verification)

• Laptop, branch worktree for id(claim/doc/group): plain-text output renders names/values raw — a newline in a tag name or value forges extra rows and duplicate author=/event= fields #1611 (only pkgs/id/src/commands/group.rs changed): full cargo test --no-default-features --lib → 825 passed, 1 failed — this test.
• Laptop, clean origin/main (211aa58) detached worktree, same test filtered: fails identically (0 passed, 1 failed). So the failure is pre-existing on main, not caused by the id(claim/doc/group): plain-text output renders names/values raw — a newline in a tag name or value forges extra rows and duplicate author=/event= fields #1611 renderer change or PR id: quote whitespace/control values in plain-text renderer so rows cannot be forged (#1611) #1703.
• The test exercises validate_world_options in pkgs/id/src/commands/serve.rs (~line 1447): names like "", "../evil", "Tic-Tac-Toe", "a/b", "sp ace", "wörld" must be refused; "tt-2_x", 64×a, "lobby" must pass; 65×a refused. One of these expectations no longer matches the implementation on main.

Acceptance

• Identify which expectation diverged (test vs validate_world_options) and whether the implementation or the test is wrong, with reasoning recorded on this issue.
• cargo test --no-default-features --lib commands::serve::tests::world_names_are_bounded_and_are_a_single_path_segment passes on main.
• Full --lib suite green (or any remaining failures filed separately).

Found while verifying PR #1703 / issue #1611; that PR's own targeted tests (7 renderer tests) pass.