Add Gemini CLI support and sponsor nudge at pipeline completion (#105)

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

tests/test_install.py

@@ -263,3 +263,58 @@ def test_cursor_uninstall_noop_if_not_installed(tmp_path):
     """cursor uninstall does nothing if rule was never written."""
     from graphify.__main__ import _cursor_uninstall
     _cursor_uninstall(tmp_path)  # should not raise
+
+
+# ── Gemini CLI ────────────────────────────────────────────────────────────────
+
+def test_gemini_install_writes_gemini_md(tmp_path):
+    from graphify.__main__ import gemini_install
+    gemini_install(tmp_path)
+    md = tmp_path / "GEMINI.md"
+    assert md.exists()
+    assert "graphify-out/GRAPH_REPORT.md" in md.read_text()
+
+def test_gemini_install_writes_hook(tmp_path):
+    import json as _json
+    from graphify.__main__ import gemini_install
+    gemini_install(tmp_path)
+    settings = _json.loads((tmp_path / ".gemini" / "settings.json").read_text())
+    hooks = settings["hooks"]["BeforeTool"]
+    assert any("graphify" in str(h) for h in hooks)
+
+def test_gemini_install_idempotent(tmp_path):
+    from graphify.__main__ import gemini_install
+    gemini_install(tmp_path)
+    gemini_install(tmp_path)
+    md = tmp_path / "GEMINI.md"
+    assert md.read_text().count("## graphify") == 1
+
+def test_gemini_install_merges_existing_gemini_md(tmp_path):
+    from graphify.__main__ import gemini_install
+    (tmp_path / "GEMINI.md").write_text("# My project rules\n")
+    gemini_install(tmp_path)
+    content = (tmp_path / "GEMINI.md").read_text()
+    assert "# My project rules" in content
+    assert "graphify-out/GRAPH_REPORT.md" in content
+
+def test_gemini_uninstall_removes_section(tmp_path):
+    from graphify.__main__ import gemini_install, gemini_uninstall
+    gemini_install(tmp_path)
+    gemini_uninstall(tmp_path)
+    md = tmp_path / "GEMINI.md"
+    assert not md.exists()
+
+def test_gemini_uninstall_removes_hook(tmp_path):
+    import json as _json
+    from graphify.__main__ import gemini_install, gemini_uninstall
+    gemini_install(tmp_path)
+    gemini_uninstall(tmp_path)
+    settings_path = tmp_path / ".gemini" / "settings.json"
+    if settings_path.exists():
+        settings = _json.loads(settings_path.read_text())
+        hooks = settings.get("hooks", {}).get("BeforeTool", [])
+        assert not any("graphify" in str(h) for h in hooks)
+
+def test_gemini_uninstall_noop_if_not_installed(tmp_path):
+    from graphify.__main__ import gemini_uninstall
+    gemini_uninstall(tmp_path)  # should not raise