feat(snapshots): sort list output by started_at across kinds

src/pobsync/commands/snapshots_list.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
+from datetime import datetime, timezone
 from pathlib import Path
-from typing import Any
+from typing import Any, Optional, Tuple
 
 from ..config.load import load_global_config, load_host_config
 from ..config.merge import build_effective_config
@@ -11,6 +12,38 @@ from ..snapshot_meta import iter_snapshot_dirs, normalize_kind, read_snapshot_me
 from ..util import sanitize_host
 
 
+def _parse_iso_z(s: Any) -> Optional[datetime]:
+    """
+    Parse timestamps like '2026-02-02T22:38:07Z' into aware UTC datetime.
+    Returns None if invalid.
+    """
+    if not isinstance(s, str) or not s:
+        return None
+    # Strictly support trailing 'Z' (UTC) to avoid locale/timezone ambiguity.
+    if not s.endswith("Z"):
+        return None
+    try:
+        dt = datetime.strptime(s, "%Y-%m-%dT%H:%M:%SZ")
+        return dt.replace(tzinfo=timezone.utc)
+    except ValueError:
+        return None
+
+
+def _sort_key(item: dict[str, Any]) -> Tuple[int, datetime, str]:
+    """
+    Sort by:
+      1) Has started_at meta (1) before missing (0)
+      2) started_at descending
+      3) dirname descending (lexicographic)
+    """
+    dt = _parse_iso_z(item.get("started_at"))
+    has_dt = 1 if dt is not None else 0
+    # Use epoch for missing to keep key comparable; has_dt separates them anyway.
+    dt2 = dt if dt is not None else datetime.fromtimestamp(0, tz=timezone.utc)
+    dirname = item.get("dirname") or ""
+    return (has_dt, dt2, dirname)
+
+
 def run_snapshots_list(prefix: Path, host: str, kind: str, limit: int, include_incomplete: bool) -> dict[str, Any]:
     host = sanitize_host(host)
     k = normalize_kind(kind)
@@ -38,20 +71,13 @@ def run_snapshots_list(prefix: Path, host: str, kind: str, limit: int, include_i
     else:
         kinds = [k]
 
-    out: list[dict[str, Any]] = []
-    remaining = limit
+    items: list[dict[str, Any]] = []
 
     for kk in kinds:
-        if remaining <= 0:
-            break
-
         for d in iter_snapshot_dirs(host_root, kk):
-            if remaining <= 0:
-                break
-
             meta = read_snapshot_meta(d)
 
-            out.append(
+            items.append(
                 {
                     "kind": kk,
                     "dirname": d.name,
@@ -64,7 +90,12 @@ def run_snapshots_list(prefix: Path, host: str, kind: str, limit: int, include_i
                     "id": meta.get("id"),
                 }
             )
-            remaining -= 1
+
+    # Global sort: newest first
+    items.sort(key=_sort_key, reverse=True)
+
+    # Apply limit after sorting
+    out = items[:limit]
 
     return {
         "ok": True,