style: capitalize "Relicario" in prose / UI / CLI help

Brand name uses capital R in user-facing text — extension UI strings,
CLI clap help / descriptions / error prose, markdown docs. Lowercase
preserved for the binary command, crate names, npm package, file
paths, env vars, and code identifiers.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

extension/manifest.json

@@ -1,6 +1,6 @@
 {
   "manifest_version": 3,
-  "name": "relicario",
+  "name": "Relicario",
   "version": "0.2.0",
   "description": "Two-factor encrypted password manager",
   "icons": {
@@ -32,7 +32,7 @@
   },
   "commands": {
     "open-vault": {
-      "description": "Open relicario vault"
+      "description": "Open Relicario vault"
     }
   },
   "web_accessible_resources": []