feat: better image handling (auto resize & max size constraints) (#26401)

AGENTS.md

@@ -9,6 +9,7 @@
 ### General Principles
 
 - Keep things in one function unless composable or reusable
+- Do not extract single-use helpers preemptively. Inline the logic at the call site unless the helper is reused, hides a genuinely complex boundary, or has a clear independent name that improves the caller.
 - Avoid `try`/`catch` where possible
 - Avoid using the `any` type
 - Use Bun APIs when possible, like `Bun.file()`