feat: add target scraper infra and retroarch buildbot scraper

scripts/scraper/targets/__init__.py

@@ -0,0 +1,48 @@
+"""Target scraper plugin discovery module.
+
+Auto-detects *_targets_scraper.py files and exposes their scrapers.
+"""
+from __future__ import annotations
+
+import importlib
+import pkgutil
+from pathlib import Path
+
+
+class BaseTargetScraper:
+    """Base class for target scrapers."""
+
+    def __init__(self, url: str = ""):
+        self.url = url
+
+    def fetch_targets(self) -> dict:
+        """Fetch targets and their core lists. Returns dict matching target YAML format."""
+        raise NotImplementedError
+
+    def write_output(self, data: dict, output_path: str) -> None:
+        """Write target data to YAML file."""
+        try:
+            import yaml
+        except ImportError:
+            raise ImportError("PyYAML required: pip install pyyaml")
+        with open(output_path, "w") as f:
+            yaml.dump(data, f, default_flow_style=False, sort_keys=False)
+
+
+_scrapers: dict[str, type] = {}
+
+
+def discover_target_scrapers() -> dict[str, type]:
+    """Auto-discover all *_targets_scraper.py modules."""
+    if _scrapers:
+        return _scrapers
+    package_dir = Path(__file__).parent
+    for finder, name, ispkg in pkgutil.iter_modules([str(package_dir)]):
+        if not name.endswith("_targets_scraper"):
+            continue
+        module = importlib.import_module(f".{name}", package=__package__)
+        platform_name = getattr(module, "PLATFORM_NAME", None)
+        scraper_class = getattr(module, "Scraper", None)
+        if platform_name and scraper_class:
+            _scrapers[platform_name] = scraper_class
+    return _scrapers