feat: experiment log append/read utilities and rich viewer

bin/log_append.py

@@ -0,0 +1,30 @@
+"""Append-only experiment log utilities."""
+import json
+import os
+from datetime import datetime, timezone
+
+LOG_PATH = os.path.expanduser('~/.claude/autoresearch/log.jsonl')
+
+
+def append_entry(entry: dict, path: str = LOG_PATH) -> None:
+    entry = dict(entry)  # don't mutate caller's dict
+    entry.setdefault('ts', datetime.now(timezone.utc).isoformat())
+    os.makedirs(os.path.dirname(os.path.abspath(path)), exist_ok=True)
+    with open(path, 'a') as f:
+        f.write(json.dumps(entry) + '\n')
+
+
+def read_entries(path: str = LOG_PATH) -> list:
+    if not os.path.exists(path):
+        return []
+    entries = []
+    with open(path) as f:
+        for line in f:
+            line = line.strip()
+            if not line:
+                continue
+            try:
+                entries.append(json.loads(line))
+            except json.JSONDecodeError:
+                pass
+    return entries