Strip logger timestamp prefix to fix e2e test

Signed-off-by: lelia <2418071+lelia@users.noreply.github.com>

Author: lelia

tests/e2e/validate-json.sh

@@ -6,22 +6,26 @@ LOG="/tmp/e2e-output.log"
 python3 -c "
 import json, sys
 
-# The JSON output is on stdout; the log may also contain stderr debug lines.
-# Find the first line that parses as valid JSON.
+# The JSON output may be prefixed with a logger timestamp (e.g. '2026-04-08 22:46:50,580: {...}').
+# Try parsing the full line first, then from the first '{' character.
 found = False
 with open('$LOG') as f:
     for line in f:
         line = line.strip()
-        if not line:
-            continue
-        try:
-            data = json.loads(line)
-            if isinstance(data, dict):
-                found = True
-                print(f'PASS: Valid JSON output with {len(data)} top-level key(s)')
-                break
-        except json.JSONDecodeError:
+        if not line or '{' not in line:
             continue
+        # Try full line first, then from the first brace
+        for candidate in (line, line[line.index('{'):]):
+            try:
+                data = json.loads(candidate)
+                if isinstance(data, dict):
+                    found = True
+                    print(f'PASS: Valid JSON output with {len(data)} top-level key(s)')
+                    break
+            except json.JSONDecodeError:
+                continue
+        if found:
+            break
 
 if not found:
     print('FAIL: No valid JSON object found in output')