fix(report): use the Keygraph wordmark on the PDF cover and link it

Replace the cover logo with the current Keygraph wordmark (dark ink on
a transparent background, cropped from the website's wordmark PNG) and
size it by height so the wide mark sits level with the brand text.
Link both the wordmark and the "AI Pentester by Keygraph" byline to
https://keygraph.io.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/worker/templates/typst/report.typ

@@ -17,6 +17,7 @@
 
 #let tester-override = sys.inputs.at("tester", default: "Shannon")
 #let brand = sys.inputs.at("brand", default: "Shannon | AI Pentester by Keygraph")
+#let keygraph-url = "https://keygraph.io"
 
 // ---------- Palette ---------------------------------------------------------
 // Kept distinct so Critical / High are not confused under monitor gamma.
@@ -228,11 +229,13 @@
   #v(3.2cm)
 
   #let brand-parts = brand.split("|").map(p => p.trim())
+  // The logo is the Keygraph wordmark (about 5:1), so it is sized by height to
+  // sit level with the two-line brand text beside it.
   #grid(
     columns: (auto, 1fr),
-    column-gutter: 8pt,
+    column-gutter: 12pt,
     align: (horizon, horizon),
-    image("/assets/keygraph-logo.png", width: 1.6cm),
+    link(keygraph-url, image("/assets/keygraph-logo.png", height: 0.5cm)),
     {
       set par(leading: 0.6em)
       text(size: 11pt, fill: ink, weight: "semibold", tracking: 1.2pt)[
@@ -240,9 +243,9 @@
       ]
       if brand-parts.len() > 1 {
         linebreak()
-        text(size: 9pt, fill: muted, weight: "regular")[
+        link(keygraph-url, text(size: 9pt, fill: muted, weight: "regular")[
           #brand-parts.slice(1).join(" ")
-        ]
+        ])
       }
     }
   )