fix(intern-decision-serve): 0.1.2 treats empty/null images as absent

Audit finding on 0.1.1: a Jev client that always sends an images array with no
images was rejected for nothing. Only a non-empty value is 422 now. Also aligns
the contract's response example with the wire (model is the name@revision
string, not an object).

Re-accepted live: images []/null -> 200, ["a.png"] -> 422; JevBench all 202/231,
hard 83/111, 0 changed rows across the bench's r1..r4 (924).

services/intern-decision-serve/uv.lock

@@ -284,7 +284,7 @@ wheels = [
 
 [[package]]
 name = "intern-decision-serve"
-version = "0.1.1"
+version = "0.1.2"
 source = { editable = "." }
 dependencies = [
     { name = "fastapi" },