feat(brand): social-card og:image + Seneschal brand assets (avatar/banner)

Author: S. K. Rotwang MMMMMMMMM

brand/seneschal-avatar.png

@@ -11,9 +11,11 @@
 <meta property="og:url" content="https://docs.seneschal.space/">
 <meta property="og:title" content="Monero &amp; Zcash payment webhooks — view-key only, no node">
 <meta property="og:description" content="A webhook the instant an XMR or ZEC payment lands at your address, from a read-only view key. Pay-per-call in USDC (x402); free read tier, no signup or API key.">
-<meta name="twitter:card" content="summary">
+<meta property="og:image" content="https://docs.seneschal.space/og.png">
+<meta name="twitter:card" content="summary_large_image">
 <meta name="twitter:title" content="Monero &amp; Zcash payment webhooks — view-key only, no node">
 <meta name="twitter:description" content="A webhook the instant an XMR or ZEC payment lands at your address, from a read-only view key. Pay-per-call in USDC (x402); free read tier.">
+<meta name="twitter:image" content="https://docs.seneschal.space/og.png">
 <script type="application/ld+json">
 {
   "@context": "https://schema.org",

brand/seneschal-banner.png

@@ -11,9 +11,11 @@
 <meta property="og:url" content="https://seneschal.space/">
 <meta property="og:title" content="Private Watch — Monero &amp; Zcash payment webhooks, view-key only">
 <meta property="og:description" content="Get pinged the instant an XMR or ZEC payment lands at your address — from a read-only view key, no node to run. $0.02/day + $0.005/webhook in USDC via x402. No signup, no API key.">
-<meta name="twitter:card" content="summary">
+<meta property="og:image" content="https://seneschal.space/og.png">
+<meta name="twitter:card" content="summary_large_image">
 <meta name="twitter:title" content="Private Watch — Monero &amp; Zcash payment webhooks, view-key only">
 <meta name="twitter:description" content="Get pinged the instant an XMR or ZEC payment lands at your address — from a read-only view key, no node. Pay-per-use in USDC via x402. No signup.">
+<meta name="twitter:image" content="https://seneschal.space/og.png">
 <script type="application/ld+json">
 {
   "@context": "https://schema.org",

docs/index.html

@@ -40,6 +40,8 @@ MAPPINGS=(
 	"robots.txt:robots.txt"
 	"robots.txt:docs/robots.txt"
 	"sitemap.xml:sitemap.xml"
+	"og.png:og.png"
+	"og.png:docs/og.png"
 )
 
 echo "Publishing docs from ${REMOTE}:${SRC}/docs to ${REMOTE}:${WEB_ROOT}"