Prepare Elgato Marketplace listing: brand author, store assets, listing text

- manifest Author -> c4ch3c4d3 and repackage .streamDeckPlugin
- scripts/store-assets.mts renders real key SVGs into store PNGs (app icon 288, thumbnail + 3 gallery 1920x960)
- store-assets/listing.md: description, tags, release notes, submission checklist

com.bryce.llamawatch.sdPlugin/manifest.json

@@ -2,7 +2,7 @@
   "$schema": "https://schemas.elgato.com/streamdeck/plugins/manifest.json",
   "Name": "llama-watch",
   "Version": "1.0.0.0",
-  "Author": "Bryce Zuccaro",
+  "Author": "c4ch3c4d3",
   "Actions": [
     {
       "Name": "In-Flight Monitor",
@@ -56,4 +56,4 @@
     "Version": "24"
   },
   "UUID": "com.bryce.llamawatch"
-}
+}