Fix header overlap in invoice PDF and Bongbetic wordmark on light theme

react-pdf wraps text once at the first flex measure; when yoga then shrank
the vendor column the cached lines ran under the INVOICE meta column. The
header now pins column widths (299 + 24 + 192 pt), sizes the logo from its
own aspect (stacked above the text when it would leave under 160 pt), uses
absolute per-Text line heights, and turns hyphenation off.

Also: repeating table header with an orphan-header guard, wrap=false rows,
Page n of N footer, GSTIN printed only when present, one Text per address
line, HTML twin header grid. The light-theme header showed the white-text
wordmark; the ternary was inverted.

Adds vitest + pdfjs-dist harness that fails on the old document (address
overlaps Invoice No.) and passes on the new one.

src/styles/carbon.scss

@@ -201,10 +201,10 @@ body {
 }
 
 .inv-top {
-  display: flex;
-  justify-content: space-between;
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) 220px;
   gap: 24px;
-  align-items: flex-start;
+  align-items: start;
 }
 
 .inv-vendor {
@@ -214,6 +214,11 @@ body {
   min-width: 0;
 }
 
+.inv-vendor > div {
+  flex: 1 1 0;
+  min-width: 0;
+}
+
 .inv-vendor__logo {
   max-height: 56px;
   max-width: 220px;
@@ -229,11 +234,12 @@ body {
 .inv-vendor__line {
   margin: 0;
   white-space: pre-line;
+  overflow-wrap: anywhere;
 }
 
 .inv-meta {
   text-align: right;
-  min-width: 220px;
+  min-width: 0;
 }
 
 .inv-meta__title {