feat: pool rebuild_manifest recovery

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

gates/pool.py

@@ -1,6 +1,7 @@
 """Pure storage layer for the Image Pool node. Stdlib only — no torch, no comfy."""
 import json
 import os
+import re
 from pathlib import Path
 
 
@@ -112,5 +113,18 @@ def set_label(base_dir, pool_id, index, label):
 
 
 def rebuild_manifest(base_dir, pool_id):
-    # Temporary stub — replaced in Task 7.
-    return empty_manifest()
+    d = pool_dir(base_dir, pool_id)
+    m = empty_manifest()
+    if not d.exists():
+        return m
+    imgs = sorted(p.name for p in d.glob("img_*.png") if not p.name.endswith(".mask.png"))
+    max_seq = 0
+    for name in imgs:
+        match = re.match(r"img_(\d+)\.png$", name)
+        seq = int(match.group(1)) if match else 0
+        max_seq = max(max_seq, seq)
+        mask_name = name.replace(".png", ".mask.png")
+        mask = mask_name if (d / mask_name).exists() else None
+        m["slots"].append({"image": name, "mask": mask, "label": "", "added": 0})
+    m["next_seq"] = max_seq + 1
+    return m

tests/test_pool.py

@@ -97,3 +97,25 @@ def test_set_label_out_of_range_noop(tmp_path):
     pool.add_image(str(tmp_path), "p1", b"a", ts=1)
     m = pool.set_label(str(tmp_path), "p1", 5, "x")
     assert m["slots"][0]["label"] == ""
+
+
+def test_rebuild_from_files(tmp_path):
+    d = tmp_path / "p1"
+    d.mkdir()
+    (d / "img_0001.png").write_bytes(b"a")
+    (d / "img_0001.mask.png").write_bytes(b"m")
+    (d / "img_0003.png").write_bytes(b"c")  # gap on purpose
+    m = pool.rebuild_manifest(str(tmp_path), "p1")
+    assert [s["image"] for s in m["slots"]] == ["img_0001.png", "img_0003.png"]
+    assert m["slots"][0]["mask"] == "img_0001.mask.png"
+    assert m["slots"][1]["mask"] is None
+    assert m["next_seq"] == 4        # max seq 3 + 1
+    assert m["active"] == 0
+
+
+def test_read_corrupt_manifest_triggers_rebuild(tmp_path):
+    d = tmp_path / "p1"; d.mkdir()
+    (d / "img_0001.png").write_bytes(b"a")
+    (d / "manifest.json").write_text("{ not json")
+    m = pool.read_manifest(str(tmp_path), "p1")
+    assert [s["image"] for s in m["slots"]] == ["img_0001.png"]