docs: coherence sweep — "no plaintext at rest" across alt banners

Align banner-A/B/C/D with the corrected hero claim: drop the false
"leaves no trace on disk" wording (gopass stores GPG ciphertext on
disk) in favor of "no plaintext at rest — GPG-encrypted on disk".

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/assets/banner-A.svg

@@ -1,4 +1,4 @@
-<svg width="1200" height="360" viewBox="0 0 1200 360" fill="none" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Incredigo (igo) — guards your credentials in locked memory, leaves no trace on disk">
+<svg width="1200" height="360" viewBox="0 0 1200 360" fill="none" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Incredigo (igo) — no plaintext at rest: decrypted secrets in locked memory, GPG-encrypted on disk">
   <defs>
     <linearGradient id="Abg" x1="0" y1="0" x2="1200" y2="360" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#161210"/><stop offset="1" stop-color="#0C0907"/></linearGradient>
     <linearGradient id="Aword" x1="360" y1="120" x2="360" y2="200" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#F7B968"/><stop offset="1" stop-color="#E8772E"/></linearGradient>
@@ -12,8 +12,8 @@
     <text x="104" y="146" text-anchor="middle" font-family="'JetBrainsMono Nerd Font','JetBrains Mono','Fira Code',monospace" font-weight="700" font-size="96" fill="url(#Aink)">go</text>
   </g>
   <text x="360" y="158" font-family="'JetBrainsMono Nerd Font','JetBrains Mono','Fira Code',monospace" font-size="68" font-weight="700" letter-spacing="3" fill="#8C5E2E"><tspan>in</tspan><tspan fill="url(#Aword)">CRED</tspan><tspan>i</tspan><tspan fill="url(#Aword)">GO</tspan></text>
-  <text x="362" y="206" font-family="'Inter','DejaVu Sans',sans-serif" font-size="25" font-weight="500" fill="#C9BBB0">Guards your credentials in locked memory.</text>
-  <text x="362" y="240" font-family="'Inter','DejaVu Sans',sans-serif" font-size="25" font-weight="500" fill="#C9BBB0">Leaves no trace on disk.</text>
+  <text x="362" y="206" font-family="'Inter','DejaVu Sans',sans-serif" font-size="25" font-weight="500" fill="#C9BBB0">Decrypted secrets live only in locked memory.</text>
+  <text x="362" y="240" font-family="'Inter','DejaVu Sans',sans-serif" font-size="25" font-weight="500" fill="#C9BBB0">No plaintext at rest — GPG-encrypted on disk.</text>
   <g font-family="'JetBrainsMono Nerd Font','JetBrains Mono',monospace" font-size="16" font-weight="600">
     <g transform="translate(362,278)"><rect width="150" height="34" rx="17" fill="#1F1611" stroke="#D9661A" stroke-width="1.5"/><text x="75" y="22" text-anchor="middle" fill="#F7B968">local-first</text></g>
     <g transform="translate(524,278)"><rect width="138" height="34" rx="17" fill="#1F1611" stroke="#D9661A" stroke-width="1.5"/><text x="69" y="22" text-anchor="middle" fill="#F7B968">RAM-only</text></g>