Bump VM memory to 2GB and add crawler rate limits

OOM crash took the site down — increase memory from 1GB to 2GB.
Add Crawl-delay to robots.txt to throttle aggressive bots.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fly.toml

@@ -41,6 +41,6 @@ primary_region = 'iad'
   DEBUG = '0'
 
 [[vm]]
-  memory = '1gb'
+  memory = '2gb'
   cpu_kind = 'shared'
   cpus = 1

templates/robots.txt

@@ -1,4 +1,23 @@
 User-agent: *
 Allow: /
+Crawl-delay: 2
+
+User-agent: GPTBot
+Crawl-delay: 5
+
+User-agent: Bytespider
+Crawl-delay: 10
+
+User-agent: AhrefsBot
+Crawl-delay: 10
+
+User-agent: SemrushBot
+Crawl-delay: 10
+
+User-agent: DotBot
+Crawl-delay: 10
+
+User-agent: MJ12bot
+Crawl-delay: 10
 
 Sitemap: https://photos.kennethreitz.org/sitemap.xml