chore(ui): remove the local browser E2E

[e54-bot]

Removes the local UI browser E2E. The owner decided it is not trusted and has low value; it left CI in #865 and must not gate merges.

Refs #862

Removed

• ui/scripts/e2e.mjs and the test:e2e script in ui/package.json
• E2E section of ui/README.md
• data-e2e attributes in ui/src/App.svelte, ui/src/lib/Dialogs.svelte, ui/src/lib/RuleView.svelte (used only by the script)
• tests/fixtures/workshop/synthetic/ui-view.ws (used only by the script)
• ADR-0032 item 10 sentence that required an E2E test
• docs/LESSONS.md: one sentence that pointed at e2e.mjs now says the E2E was deleted; history kept

No dependencies or ignore rules existed for it (the script used no browser driver).

Verified

npm run check, npm test (18 pass), npm run build, npm run check:size, actionlint, git diff --check; grep shows no remaining reference. CI UI job unchanged.

Follow-up

None needed. The wright ui server is covered by its own Rust tests (crates/wright-cli/tests/ui.rs), so no product code existed only for the E2E. ADR-0032 may still deserve an owner decision on whether a future editing layer needs its own end-to-end check.

[Teakowa]

Approve (round 1).

Checks

1. The removal is complete. ui/scripts/e2e.mjs, the test:e2e script, the ui/README.md section, and the ui-view.ws fixture are gone. On the PR head, git grep for data-e2e, ui-view, test:e2e and e2e.mjs finds nothing outside CHANGELOG.md, which is release history and correctly untouched. .github on main has no E2E reference.
2. Scope: nine files, 22 added and 633 removed lines. The App.svelte, Dialogs.svelte and RuleView.svelte changes only drop the data-e2e attributes. I found no other change in them. git diff --check is clean.
3. Local checks on the PR head: npm ci, npm run check (127 files, 0 errors, 0 warnings), npm test (18 of 18), npm run build and npm run check:size (21.5 KiB gzipped, budget 100) all pass. CI UI is green. Rust (stable) / Quality and Product integration were still pending at review time.
4. The commit message and PR body say Refs #862 and carry no Fixes. This is correct, because the PR removes the flaky test and does not close the issue.

Non-blocking

• docs/adr/0032-structured-editor-form-factor.md loses an acceptance sentence for item 10 (an end-to-end edit test). The PR body says the owner decided this, and it flags a possible future decision for the editing layer. Please link that owner decision, or a follow-up issue, from the ADR or the PR so the ADR does not silently lose a requirement.
• Check that #862 ends in the right state: with the E2E deleted, the issue's openRule(4, 'after') timeout can no longer occur. Close it with a note, or leave it, but record the choice.