short <? tags turned into <?php: the page was unusable in the browser

short <? tags turned into <?php: the page was unusable in the browser

109 occurrences of "<? echo ... ?>" in web/index.php (48) and
web/briskin5/index.php (61). Short tags only work with short_open_tag = On,
which is Off by default in php and is Off on debian 13; on the production
machine (debian 8) it is evidently On.

This is not a cosmetic problem. Without interpretation the text of the tag
ends up literally in the html, and in a javascript context such as

    var g_tables_n = <? echo TABLES_N; ?>;

it becomes a syntax error that prevents the compilation of the WHOLE <script>
block. As a consequence none of the variables declared in there is created,
"sess" included, and the room page is unusable: the browser console reports
"sess is not defined" and the buttons do nothing.

Every src/href with cache busting was broken too
("commons.js?v=<? echo BSK_BUSTING; ?>"), and now renders properly
("commons.js?v=997ebdc").

Converted to <?php instead of turning short_open_tag on: the directive is
discouraged and not guaranteed, while the explicit form works everywhere.
All 109 occurrences had the identical shape "<? echo", and none of them fell
inside a php string, so the substitution is mechanical. Checked that the
generated page no longer contains uninterpreted tags.

Found by the user opening the site with a real browser: it is the first
defect that came from the javascript client, which the curl tests could not
detect because they do not execute the page.

NOTE: this commit also carries two pre-existing changes from the working
copy, unrelated to the tag conversion: the inclusion of custom.js in
index.php (two lines) and $brisk_donate passed to $brisk_vertical_menu. They
were already there and were picked up by the "git add" of the whole file.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014M1jiEq9cHdE5SE5j6vFuE