feat(wiki): concept schema loader + concepts.yaml (F-12)

Adds wiki/concepts.yaml (5 curated seeds: discrete-conformal-map,
circle-packing, lobachevsky-function, discrete-yamabe-flow,
hyperideal-tetrahedron) and codex/wiki.py with full load_concepts()
implementation (Concept dataclass, YAML parser, graceful empty list).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/wiki/test_check.py

@@ -0,0 +1,163 @@
+"""Tests for ``codex wiki check`` CLI command.
+
+Verifies:
+- Exit 0 when all pages are grounded (no ⚠ in any page).
+- Exit 1 when at least one page contains an ungrounded claim (⚠ marker).
+"""
+
+from __future__ import annotations
+
+import textwrap
+from pathlib import Path
+
+import pytest
+from typer.testing import CliRunner
+
+from codex.cli import app
+
+# ---------------------------------------------------------------------------
+# Fixtures
+# ---------------------------------------------------------------------------
+
+
+@pytest.fixture
+def wiki_dir_all_grounded(tmp_path: Path) -> Path:
+    """Create a wiki directory with only grounded pages (no ⚠)."""
+    wiki = tmp_path / "wiki"
+    wiki.mkdir()
+
+    (wiki / "discrete-conformal-map.md").write_text(
+        textwrap.dedent(
+            """\
+            # Discrete Conformal Map
+
+            A discrete conformal map is defined by logarithmic scale factors. [BPS2015 #chunk 0]
+            The variational principle gives the optimum. [BPS2015 #chunk 1]
+            """
+        ),
+        encoding="utf-8",
+    )
+    (wiki / "circle-packing.md").write_text(
+        textwrap.dedent(
+            """\
+            # Circle Packing
+
+            Circle packing is studied via the Koebe-Andreev-Thurston theorem. [Thurston1985 #page 3]
+            """
+        ),
+        encoding="utf-8",
+    )
+    return wiki
+
+
+@pytest.fixture
+def wiki_dir_with_ungrounded(tmp_path: Path) -> Path:
+    """Create a wiki directory where one page has an ungrounded claim (⚠)."""
+    wiki = tmp_path / "wiki"
+    wiki.mkdir()
+
+    (wiki / "lobachevsky-function.md").write_text(
+        textwrap.dedent(
+            """\
+            # Lobachevsky Function
+
+            The volume formula is V = L(γ₁)+L(γ₂)+L(γ₃). [Springborn2008 #chunk 16]
+            ⚠ The closed form L(x) = -∫₀ˣ log|2 sin t| dt. [Springborn2008 #chunk 99]
+            """
+        ),
+        encoding="utf-8",
+    )
+    return wiki
+
+
+# ---------------------------------------------------------------------------
+# Tests
+# ---------------------------------------------------------------------------
+
+
+def test_wiki_check_exit_0_when_all_grounded(
+    wiki_dir_all_grounded: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """codex wiki check exits 0 when no ⚠ in any page."""
+    from unittest.mock import MagicMock
+
+    from codex.config import Settings
+
+    mock_settings = MagicMock(spec=Settings)
+    mock_settings.wiki_dir = str(wiki_dir_all_grounded)
+    monkeypatch.setattr("codex.cli.get_settings", lambda: mock_settings, raising=False)
+
+    runner = CliRunner()
+    result = runner.invoke(app, ["wiki", "check", "--output-dir", str(wiki_dir_all_grounded)])
+    assert result.exit_code == 0, (
+        f"Expected exit 0, got {result.exit_code}. Output: {result.output}"
+    )
+
+
+def test_wiki_check_exit_1_when_ungrounded(
+    wiki_dir_with_ungrounded: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """codex wiki check exits 1 when at least one ⚠ is present."""
+    from unittest.mock import MagicMock
+
+    from codex.config import Settings
+
+    mock_settings = MagicMock(spec=Settings)
+    mock_settings.wiki_dir = str(wiki_dir_with_ungrounded)
+    monkeypatch.setattr("codex.cli.get_settings", lambda: mock_settings, raising=False)
+
+    runner = CliRunner()
+    result = runner.invoke(app, ["wiki", "check", "--output-dir", str(wiki_dir_with_ungrounded)])
+    assert result.exit_code == 1, (
+        f"Expected exit 1, got {result.exit_code}. Output: {result.output}"
+    )
+
+
+def test_wiki_check_empty_dir_exits_0(
+    tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """codex wiki check exits 0 when wiki dir has no .md pages (nothing to check)."""
+    wiki = tmp_path / "wiki"
+    wiki.mkdir()
+
+    from unittest.mock import MagicMock
+
+    from codex.config import Settings
+
+    mock_settings = MagicMock(spec=Settings)
+    mock_settings.wiki_dir = str(wiki)
+    monkeypatch.setattr("codex.cli.get_settings", lambda: mock_settings, raising=False)
+
+    runner = CliRunner()
+    result = runner.invoke(app, ["wiki", "check", "--output-dir", str(wiki)])
+    assert result.exit_code == 0
+
+
+def test_wiki_check_index_and_log_ignored(
+    tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """codex wiki check ignores index.md and log.md even if they contain ⚠."""
+    wiki = tmp_path / "wiki"
+    wiki.mkdir()
+
+    # index.md and log.md with ⚠ — must NOT trigger exit 1
+    (wiki / "index.md").write_text("# Wiki Index\n\n⚠ some note\n", encoding="utf-8")
+    (wiki / "log.md").write_text("# Log\n\n⚠ ungrounded\n", encoding="utf-8")
+
+    from unittest.mock import MagicMock
+
+    from codex.config import Settings
+
+    mock_settings = MagicMock(spec=Settings)
+    mock_settings.wiki_dir = str(wiki)
+    monkeypatch.setattr("codex.cli.get_settings", lambda: mock_settings, raising=False)
+
+    runner = CliRunner()
+    result = runner.invoke(app, ["wiki", "check", "--output-dir", str(wiki)])
+    assert result.exit_code == 0, (
+        f"index.md / log.md should be excluded. exit={result.exit_code}, out={result.output}"
+    )