Stop hanging after KiCad folder permission.

Apri progetto walked every nested file (HubAudio .history ~2000) so
onFilesChange never ran and Next stayed disabled. Read only kicad_pro,
sch, and pcb in the project dir; timeout to an error; enable Next when
.kicad_pro is in.

tests/test_kicad_project.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import json
+import re
 from pathlib import Path
 
 import pytest
@@ -321,3 +322,87 @@ def test_real_hubaudio_kicad_pro_filename_and_folder_ingest(tmp_path: Path):
     parts, _nets, fmt = parse_netlist_any(parsed.root)
     assert fmt == "kicad_sch"
     assert "U13" not in parts
+
+
+# Mirrors periscope/src/frontend/src/lib/kicad-project-files.ts (folder walk + Next).
+def _skip_walk_dir_name(name: str) -> bool:
+    n = name.rstrip("/").lower()
+    if not n or n.startswith("."):
+        return True
+    return bool(re.search(r"(-backups|\.pretty|3dmodels|__macosx|node_modules)$", n))
+
+
+def _is_kicad_project_file_name(name: str) -> bool:
+    base = name.replace("\\", "/").rsplit("/", 1)[-1].lower()
+    return base.endswith((".kicad_pro", ".kicad_sch", ".kicad_pcb"))
+
+
+def _skip_rel(rel: str) -> bool:
+    parts = [p for p in rel.replace("\\", "/").lower().split("/") if p]
+    return any(_skip_walk_dir_name(p) for p in parts)
+
+
+def _details_step_ready(project_name: str, files: list[dict[str, str]]) -> bool:
+    if not project_name.strip():
+        return False
+    return any(_looks_like_kicad_pro(f.get("name", ""), f.get("webkitRelativePath", "")) for f in files)
+
+
+def test_folder_walk_skips_history_and_keeps_project_dir_only():
+    """Live 2.60.8 recursed handle.entries() into HubAudio/.history (~2000 files) so Next never enabled."""
+    names = [
+        "HubAudio.kicad_pro",
+        "HubAudio.kicad_sch",
+        "Codec.kicad_sch",
+        "HubAudio.kicad_pcb",
+        "HubAudio.kicad_prl",
+        "~HubAudio.kicad_pcb.lck",
+        ".history",
+        ".git",
+        "fp-lib-table",
+    ]
+    kept = [n for n in names if _is_kicad_project_file_name(n)]
+    skipped_dirs = [n for n in names if _skip_walk_dir_name(n)]
+    assert kept == [
+        "HubAudio.kicad_pro",
+        "HubAudio.kicad_sch",
+        "Codec.kicad_sch",
+        "HubAudio.kicad_pcb",
+    ]
+    assert ".history" in skipped_dirs and ".git" in skipped_dirs
+    assert _skip_rel("HubAudio/.history/objects/aa")
+    assert not _skip_rel("HubAudio/HubAudio.kicad_pro")
+
+
+def test_details_next_enables_when_kicad_pro_is_in():
+    empty: list[dict[str, str]] = []
+    assert not _details_step_ready("HubAudio", empty)
+    assert not _details_step_ready(
+        "",
+        [{"name": "HubAudio.kicad_pro", "webkitRelativePath": "HubAudio/HubAudio.kicad_pro"}],
+    )
+    assert _details_step_ready(
+        "HubAudio",
+        [{"name": "HubAudio.kicad_pro", "webkitRelativePath": "HubAudio/HubAudio.kicad_pro"}],
+    )
+    assert _details_step_ready(
+        "HubAudio",
+        [{"name": "HubAudio", "webkitRelativePath": "HubAudio/HubAudio.kicad_pro"}],
+    )
+
+
+@pytest.mark.skipif(not (HUBAUDIO / "HubAudio.kicad_pro").is_file(), reason="HubAudio tree not on disk")
+def test_real_hubaudio_recursive_tree_is_huge_project_dir_is_small():
+    tree = list(HUBAUDIO.rglob("*"))
+    project_dir = [
+        p
+        for p in HUBAUDIO.iterdir()
+        if p.is_file() and _is_kicad_project_file_name(p.name)
+    ]
+    assert len(tree) > 100
+    assert (HUBAUDIO / ".history").is_dir()
+    assert any(p.name == "HubAudio.kicad_pro" for p in project_dir)
+    assert any(p.name.endswith(".kicad_sch") for p in project_dir)
+    assert any(p.name.endswith(".kicad_pcb") for p in project_dir)
+    assert all(".history" not in str(p) for p in project_dir)
+    assert len(project_dir) < 40