Bug fix — Issue #602: XLS export fatals on every report controller

Symptom

Clicking "Export as spreadsheet" on any legacy results report ended in HTTP 500: Uncaught Error: Class "PhpOffice\PhpSpreadsheet\Style\Border" not found (first use at lib/results/baselinel1l2.php:564, initStyleSpreadsheet). Every attempt also logged 4 E_WARNING events (include_once(PhpOffice\...\Border.class.php), Composer\Pcre\Preg.class.php) into the Event Viewer.

Root cause

The committed vendor/ tree contains phpoffice/phpspreadsheet (plus markbaker/complex, markbaker/matrix, composer/pcre, myclabs/php-enum, maennchen/zipstream-php, nyholm/*, slim/psr7, laminas/laminas-diactoros, http-interop/http-factory-guzzle, fig/http-message-util), but the composer autoloader files were never regenerated after those packages were added:

• vendor/composer/autoload_psr4.php / autoload_static.php had no prefix mapping for any of them (class_exists('PhpOffice\...') === false);
• vendor/composer/installed.json does not list them either, so a plain composer dump-autoload would reproduce the same broken state.

After the classmap miss, TestLink's own legacy autoloader fallback tried PhpOffice\...\Border.class.php (old .class.php naming) → E_WARNING spam, then fatal on first use.

Fix approach

1. Autoloader maps — hand-added the missing PSR-4 prefixes (exactly what composer dump-autoload would emit for these packages) to both autoload_psr4.php and autoload_static.php. Chosen over re-running composer because the composer metadata does not know the packages; chosen over patching controllers because it fixes all consumers at once.
2. Null statistics sections — with autoload fixed the exporters advanced and new PHP 8 fatals surfaced: they bind data sources by reference to $gui->statistics->{priorities,keywords,platform,...} which are absent for many report configurations (reference auto-vivifies to null → count(null) TypeError; baselinel1l2 even swaps statistics to an array for its HTML template). New helper xlsDefaultStatsSections() in lib/results/displayMgr.php defaults every consumed section up-front; wired into baselinel1l2, execTimelineStats, resultsByTSuite, resultsGeneral, testAutomationSpec.
3. Legacy style keys — PhpSpreadsheet silently ignores PHPExcel-era keys (style, outline, vertical, type, startcolor), so exported sheets lost borders/fills. New helper xlsNormalizeLegacyStyles() converts them (outline expands to explicit left/right/top/bottom edges; inside-only separators have no range equivalent and are dropped); used by all nine initStyleSpreadsheet() implementations.
4. neverRunByPP — direct page access fataled on array_flip(null) when no platform set was posted; one-line (array) cast.

Verification

XLS exports of baselinel1l2, resultsByTSuite, resultsGeneral, execTimelineStats, resultsTC and resultsTCFlat now return HTTP 200 with valid OLE binary workbooks; no new Error/Warning events. Full matrix in tmp/TLU_Test_Cases.md, suite #602.

Files changed

• vendor/composer/autoload_psr4.php, vendor/composer/autoload_static.php
• lib/results/displayMgr.php (two new helpers)
• lib/results/{baselinel1l2,execTimelineStats,resultsByTSuite,resultsGeneral,testAutomationSpec}.php (guard call)
• lib/results/{baselinel1l2,execTimelineStats,neverRunByPP,resultsByStatus,resultsByTSuite,resultsGeneral,resultsTC,resultsTCAbsoluteLatest,testAutomationSpec}.php (style normalization)
• lib/results/neverRunByPP.php (array_flip guard)

Known follow-up

testAutomationSpec.php fatals on any request via specview.php:860 array_keys(null) when get_last_active_version() returns null — unrelated to export/autoload, tracked separately.