fix: add canonical URLs, unique meta descriptions, and hreflang tags

- Add canonical URL to all pages
- Fix duplicate meta descriptions across 4 pages
- Add hreflang tags for en/ja/zh-CN/x-default
- Remove llms.txt rewrite rule causing 500 error in .htaccess

.htaccess

@@ -10,7 +10,6 @@ RewriteRule ^(.*)$ https://amipro.me/$1 [L,R=301]
 # === Serve static robots.txt and sitemap.xml directly (bypass WordPress) ===
 RewriteRule ^robots\.txt$ /robots.txt [L]
 RewriteRule ^sitemap\.xml$ /sitemap.xml [L]
-RewriteRule ^llms\.txt$ /llms.txt [L]
 
 # === Security Headers ===
 <IfModule mod_headers.c>