feat(web): display logs newest-first in web gateway UI (#369)

Reverse log display order so the most recent entries appear at the top,
removing the need to scroll to see latest activity.

Frontend: rename appendLogEntry to prependLogEntry, use prepend() for
DOM insertion, cap oldest entries from the bottom, and auto-scroll to
top. Backend: update recent_entries() doc comment to clarify the
oldest-first return order works correctly with the frontend's prepend.

Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>

Cargo.lock

@@ -5032,6 +5032,12 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "sha1_smol"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbfa15b3dddfee50a0fff136974b3e1bde555604ba463834a7eb7deb6417705d"
+
 [[package]]
 name = "sha2"
 version = "0.10.9"
@@ -6207,6 +6213,7 @@ dependencies = [
  "getrandom 0.4.1",
  "js-sys",
  "serde_core",
+ "sha1_smol",
  "wasm-bindgen",
 ]