feat(cli): add --repo and --exclude filtering (fixes #5)

Add argparse-based CLI parsing with repeatable --repo/-r (include) and
--exclude/-x (exclude) options. Filtering is case-insensitive substring
matching, applied post-fetch in collect_all() per ADR-005.

- parse_args() separated from main() for testability
- main(argv=None) accepts argv for test injection
- collect_all() gains optional include/exclude parameters
- 14 new tests (8 filtering + 6 CLI parsing/integration)
- All 51 tests pass, backward compatible (no args = v1.0.0 behavior)

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

tests/test_collector.py

@@ -128,3 +128,81 @@ class TestCollectAll:
         assert result[0].is_fork is True
         assert result[0].is_archived is True
         assert result[0].is_mirror is True
+
+
+class TestCollectAllFiltering:
+    """Test collect_all filtering (include/exclude)."""
+
+    def _setup_client(self, repo_names: list[str]) -> MagicMock:
+        """Create a mock client returning repos with the given names."""
+        client = MagicMock()
+        client.get_repos.return_value = [
+            _make_repo(name=n, full_name=f"admin/{n}") for n in repo_names
+        ]
+        client.get_latest_release.return_value = None
+        client.get_milestones.return_value = []
+        return client
+
+    def test_no_filter_returns_all(self):
+        """Without include/exclude, all repos are returned (backward compat)."""
+        client = self._setup_client(["alpha", "beta", "gamma"])
+
+        result = collect_all(client)
+
+        assert [r.name for r in result] == ["alpha", "beta", "gamma"]
+
+    def test_include_single(self):
+        """Include filters repos by substring match."""
+        client = self._setup_client(["gitea-dashboard", "infra-core", "notes"])
+
+        result = collect_all(client, include=["dashboard"])
+
+        assert [r.name for r in result] == ["gitea-dashboard"]
+
+    def test_include_multiple(self):
+        """Multiple include patterns are OR-combined."""
+        client = self._setup_client(["gitea-dashboard", "infra-core", "notes"])
+
+        result = collect_all(client, include=["dashboard", "infra"])
+
+        assert [r.name for r in result] == ["gitea-dashboard", "infra-core"]
+
+    def test_exclude_single(self):
+        """Exclude removes repos matching the substring."""
+        client = self._setup_client(["gitea-dashboard", "old-fork", "notes"])
+
+        result = collect_all(client, exclude=["fork"])
+
+        assert [r.name for r in result] == ["gitea-dashboard", "notes"]
+
+    def test_include_and_exclude(self):
+        """Include is applied first, then exclude."""
+        client = self._setup_client(["projet-web", "projet-old", "infra"])
+
+        result = collect_all(client, include=["projet"], exclude=["old"])
+
+        assert [r.name for r in result] == ["projet-web"]
+
+    def test_case_insensitive(self):
+        """Filtering is case-insensitive."""
+        client = self._setup_client(["Gitea-Dashboard", "infra"])
+
+        result = collect_all(client, include=["dashboard"])
+
+        assert [r.name for r in result] == ["Gitea-Dashboard"]
+
+    def test_no_match_returns_empty(self):
+        """Returns empty list when no repo matches include filter."""
+        client = self._setup_client(["alpha", "beta"])
+
+        result = collect_all(client, include=["inexistant"])
+
+        assert result == []
+
+    def test_exclude_all_returns_empty(self):
+        """Returns empty list when all repos are excluded."""
+        client = self._setup_client(["alpha", "beta"])
+
+        result = collect_all(client, exclude=["alpha", "beta"])
+
+        assert result == []