feat(web): drop the empty terms checkbox from registration

The register step asked the user to accept "the terms of use" with no terms
linked anywhere — ceremony accepting nothing on a friends-only tool (UX review
C4). Remove the checkbox and the server-side acceptance requirement; only a
display name is required now.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/web/views.templ

@@ -380,8 +380,8 @@ templ DetailPage(r store.SummaryRow) {
 }
 
 // RegisterPage is the explicit registration step (ADR-012): an authenticated Dex
-// subject with no tapir user picks a display name and accepts the terms to create
-// their account. errMsg, when set, reports a validation problem on the prior POST.
+// subject with no tapir user picks a display name to create their account.
+// errMsg, when set, reports a validation problem on the prior POST.
 templ RegisterPage(email, errMsg string) {
 	@Layout("Tapir — Register") {
 		<article class="register">
@@ -398,10 +398,6 @@ templ RegisterPage(email, errMsg string) {
 					Display name
 					<input type="text" name="display_name" required autofocus/>
 				</label>
-				<label class="checkbox">
-					<input type="checkbox" name="accept_terms" value="yes" required/>
-					I accept the terms of use
-				</label>
 				<button type="submit" class="btn">Register</button>
 			</form>
 		</article>