feat: replace pr_review with spec-driven CI gates and pr-review skill

Add validate_spec, check_pr_size, fast_molecule, nightly_gate, and
create_dependency_pr CI modules. Remove the monolithic pr_review module
and its tests. Replace pr_review CI steps with validate_spec + check_pr_size
+ curl-based APPROVE. Add spec-driven-development and pr-review skills.
Remove dead get_reviewer_token. Update translations and AGENTS.md.

Closes DEVX-155

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

tests/unit/test_check_pr_size.py

@@ -0,0 +1,132 @@
+"""Unit tests for devx.ci.check_pr_size."""
+
+from unittest.mock import MagicMock, patch
+
+from click.testing import CliRunner
+
+from devx.ci.check_pr_size import (
+    check_size,
+    cli,
+    get_diff_stats,
+    is_excluded,
+)
+
+
+class TestIsExcluded:
+    def test_excludes_changelog(self) -> None:
+        assert is_excluded("CHANGELOG.md", ["CHANGELOG.md"])
+
+    def test_excludes_svg_glob(self) -> None:
+        assert is_excluded("docs/badges/coverage.svg", ["*.svg"])
+
+    def test_does_not_exclude_source(self) -> None:
+        assert not is_excluded("src/devx/ci/check_pr_size.py", ["CHANGELOG.md", "*.svg"])
+
+    def test_excludes_readme(self) -> None:
+        assert is_excluded("README.md", ["README.md"])
+
+
+class TestCheckSize:
+    def test_under_limits_passes(self) -> None:
+        stats = [("src/main.py", 100, 50), ("tests/test_main.py", 80, 20)]
+        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=[])
+        assert ok is True
+        assert "250" in detail  # 100+50+80+20
+
+    def test_over_lines_fails(self) -> None:
+        stats = [("src/main.py", 300, 300)]
+        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=[])
+        assert ok is False
+        assert "600" in detail
+
+    def test_over_files_fails(self) -> None:
+        stats = [(f"src/file{i}.py", 10, 5) for i in range(15)]
+        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=[])
+        assert ok is False
+        assert "15" in detail
+
+    def test_excluded_files_not_counted(self) -> None:
+        stats = [("CHANGELOG.md", 500, 500), ("src/main.py", 10, 5)]
+        ok, detail = check_size(stats, max_lines=500, max_files=10, excluded_patterns=["CHANGELOG.md"])
+        assert ok is True
+        assert "15" in detail  # only 10+5
+
+    def test_empty_stats_passes(self) -> None:
+        ok, detail = check_size([], max_lines=500, max_files=10, excluded_patterns=[])
+        assert ok is True
+
+
+class TestGetDiffStats:
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_parses_numstat_output(self, mock_run: MagicMock) -> None:
+        mock_run.return_value = MagicMock(
+            returncode=0,
+            stdout="10\t5\tsrc/main.py\n20\t10\ttests/test_main.py\n",
+            stderr="",
+        )
+        stats = get_diff_stats("origin/master", "HEAD")
+        assert len(stats) == 2
+        assert stats[0] == ("src/main.py", 10, 5)
+        assert stats[1] == ("tests/test_main.py", 20, 10)
+
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_handles_binary_files(self, mock_run: MagicMock) -> None:
+        mock_run.return_value = MagicMock(
+            returncode=0,
+            stdout="-\t-\timage.png\n",
+            stderr="",
+        )
+        stats = get_diff_stats("origin/master", "HEAD")
+        assert len(stats) == 1
+        assert stats[0] == ("image.png", 0, 0)
+
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_empty_output(self, mock_run: MagicMock) -> None:
+        mock_run.return_value = MagicMock(returncode=0, stdout="", stderr="")
+        stats = get_diff_stats("origin/master", "HEAD")
+        assert stats == []
+
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_git_diff_failure_raises(self, mock_run: MagicMock) -> None:
+        import pytest
+
+        mock_run.return_value = MagicMock(returncode=1, stdout="", stderr="fatal: bad ref")
+        with pytest.raises(Exception, match="git diff|bad ref"):
+            get_diff_stats("origin/master", "HEAD")
+
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_malformed_line_skipped(self, mock_run: MagicMock) -> None:
+        mock_run.return_value = MagicMock(
+            returncode=0,
+            stdout="not_a_valid_line\n10\t5\tsrc/main.py\n",
+            stderr="",
+        )
+        stats = get_diff_stats("origin/master", "HEAD")
+        assert len(stats) == 1
+        assert stats[0] == ("src/main.py", 10, 5)
+
+
+class TestCli:
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_passes_when_small(self, mock_run: MagicMock) -> None:
+        mock_run.return_value = MagicMock(
+            returncode=0,
+            stdout="10\t5\tsrc/main.py\n",
+            stderr="",
+        )
+        runner = CliRunner()
+        result = runner.invoke(cli, ["--base", "origin/master", "--head", "HEAD"])
+        assert result.exit_code == 0
+        assert "OK" in result.output
+
+    @patch("devx.ci.check_pr_size.subprocess.run")
+    def test_fails_when_too_large(self, mock_run: MagicMock) -> None:
+        mock_run.return_value = MagicMock(
+            returncode=0,
+            stdout="300\t300\tsrc/main.py\n",
+            stderr="",
+        )
+        runner = CliRunner()
+        result = runner.invoke(cli, ["--base", "origin/master", "--head", "HEAD", "--max-lines", "500"])
+        assert result.exit_code != 0
+        assert "600" in result.output