diff --git a/tests/test_palier4.py b/tests/test_palier4.py
new file mode 100644
index 0000000..e98ed9a
--- /dev/null
+++ b/tests/test_palier4.py
@@ -0,0 +1,146 @@
+"""Palier 4 (0.6.0): QA column, label reconciliation, wallboard."""
+
+from fastapi.testclient import TestClient
+
+import app.main as main
+from app import models
+from tests.conftest import _issue, csrf_from
+
+
+def _column_block(html: str, column: str) -> str:
+    blocks = html.split('<div class="kanban-column"')
+    for block in blocks[1:]:
+        if f'data-column="{column}"' in block.split(">", 1)[0]:
+            return block
+    raise AssertionError(f"column {column} not found")
+
+
+def _labelled(number: int, title: str, label_names: list[str]) -> dict:
+    issue = _issue(number, title)
+    issue["labels"] = [
+        {"id": 900 + i, "name": name, "color": "8b5cf6"}
+        for i, name in enumerate(label_names)
+    ]
+    return issue
+
+
+# ── QA column ─────────────────────────────────────────────────────
+
+
+def test_board_has_six_columns_including_qa(client):
+    r = client.get("/board/Projets/demo")
+    assert r.status_code == 200
+    assert "🧪 QA" in r.text
+    positions = [
+        r.text.index(f'data-column="{col}"')
+        for col in ("backlog", "todo", "in_progress", "qa", "review", "done")
+    ]
+    assert positions == sorted(positions)  # QA between in_progress and review
+
+
+def test_move_to_qa_syncs_kanban_qa_label(client, fake_gitea):
+    token = csrf_from(client)
+    r = client.post(
+        "/api/move",
+        data={
+            "repo_full_name": "Projets/demo", "issue_number": 1,
+            "to_column": "qa", "from_column": "backlog",
+            "to_order": "1", "from_order": "5", "csrf_token": token,
+        },
+    )
+    assert r.status_code == 200
+    assert r.json()["label_sync"] == "ok"
+    assert ("add", 1, "kanban:qa") in fake_gitea.label_ops
+    state = models.get_board_state("Projets/demo")
+    assert 1 in [c["issue_number"] for c in state["qa"]]
+
+
+def test_qa_cards_appear_in_focus(client, fake_gitea):
+    models.move_issue("Projets/demo", 5, "qa")
+    r = client.get("/focus")
+    assert r.status_code == 200
+    assert "Tâche focus" in r.text
+    assert "🧪 QA" in r.text
+
+
+# ── Label reconciliation (adoption) ───────────────────────────────
+
+
+def test_board_adopts_diverging_kanban_label(client, fake_gitea):
+    fake_gitea.issues["Projets/demo"].append(
+        _labelled(9, "Déplacée via Gitea", ["kanban:review"])
+    )
+    r = client.get("/board/Projets/demo")
+    assert r.status_code == 200
+    assert "Déplacée via Gitea" in _column_block(r.text, "review")
+    state = models.get_board_state("Projets/demo")
+    assert 9 in [c["issue_number"] for c in state["review"]]
+    events = [
+        e for e in models.get_events("Projets/demo") if e["issue_number"] == 9
+    ]
+    assert any(
+        e["event_type"] == "moved" and e["to_column"] == "review"
+        and e["source"] == "gitea"
+        for e in events
+    )
+
+
+def test_board_ignores_conflicting_kanban_labels(client, fake_gitea):
+    fake_gitea.issues["Projets/demo"].append(
+        _labelled(9, "Étiquettes en conflit", ["kanban:todo", "kanban:review"])
+    )
+    r = client.get("/board/Projets/demo")
+    assert r.status_code == 200
+    assert "Étiquettes en conflit" in _column_block(r.text, "backlog")
+    state = models.get_board_state("Projets/demo")
+    elsewhere = [
+        c["issue_number"]
+        for col, cards in state.items() if col != "backlog"
+        for c in cards
+    ]
+    assert 9 not in elsewhere
+
+
+def test_adoption_is_idempotent(client, fake_gitea):
+    fake_gitea.issues["Projets/demo"].append(
+        _labelled(9, "Stable", ["kanban:qa"])
+    )
+    client.get("/board/Projets/demo")
+    client.get("/board/Projets/demo")
+    events = [
+        e for e in models.get_events("Projets/demo")
+        if e["issue_number"] == 9 and e["event_type"] == "moved"
+    ]
+    assert len(events) == 1  # adopted once, then label and state agree
+
+
+# ── Wallboard ─────────────────────────────────────────────────────
+
+
+def test_wall_renders_active_projects(client):
+    models.move_issue("Projets/demo", 5, "in_progress")
+    r = client.get("/wall")
+    assert r.status_code == 200
+    assert "Projets/demo" in r.text
+    assert "Tâche focus" in r.text  # the in-progress card is on the wall
+    assert 'class="wall-slide active"' in r.text
+    assert "🧪 QA" in r.text  # the six column counters include QA
+
+
+def test_wall_single_repo_mode(client):
+    r = client.get("/wall", params={"repo": "Projets/demo"})
+    assert r.status_code == 200
+    assert "Projets/demo" in r.text
+
+
+def test_wall_unknown_repo_shows_empty_state(client):
+    r = client.get("/wall", params={"repo": "Inconnu/xyz"})
+    assert r.status_code == 200
+    assert "Aucun projet actif" in r.text
+
+
+def test_wall_is_behind_auth(monkeypatch, fake_gitea):
+    monkeypatch.setenv("KANBANTE_AUTH_USER", "bruno")
+    monkeypatch.setenv("KANBANTE_AUTH_PASSWORD", "motdepasse")
+    with TestClient(main.app) as secured:
+        assert secured.get("/wall").status_code == 401