v2: automated BIOS platform with full pipeline

Reorganized 6 branches into bios/Manufacturer/Console/.
Scrapers for RetroArch, Batocera, Recalbox, and libretro core-info.
Platform-aware verification replicating native logic per platform.
Pack generation with dedup, alias resolution, variant support.
CI/CD: weekly auto-scrape, auto-release, PR validation.
Large files (>50MB) stored as GitHub Release assets, auto-fetched at build time.

scripts/scraper/base_scraper.py

@@ -0,0 +1,155 @@
+"""Base scraper interface for platform BIOS requirement sources."""
+
+from __future__ import annotations
+
+import json
+import urllib.request
+import urllib.error
+from abc import ABC, abstractmethod
+from dataclasses import dataclass, field
+
+
+@dataclass
+class BiosRequirement:
+    """A single BIOS file requirement from a platform source."""
+    name: str
+    system: str
+    sha1: str | None = None
+    md5: str | None = None
+    crc32: str | None = None
+    size: int | None = None
+    destination: str = ""
+    required: bool = True
+    zipped_file: str | None = None  # If set, md5 is for this ROM inside the ZIP
+
+
+@dataclass
+class ChangeSet:
+    """Differences between scraped requirements and current config."""
+    added: list[BiosRequirement] = field(default_factory=list)
+    removed: list[BiosRequirement] = field(default_factory=list)
+    modified: list[tuple[BiosRequirement, BiosRequirement]] = field(default_factory=list)
+
+    @property
+    def has_changes(self) -> bool:
+        return bool(self.added or self.removed or self.modified)
+
+    def summary(self) -> str:
+        parts = []
+        if self.added:
+            parts.append(f"+{len(self.added)} added")
+        if self.removed:
+            parts.append(f"-{len(self.removed)} removed")
+        if self.modified:
+            parts.append(f"~{len(self.modified)} modified")
+        return ", ".join(parts) if parts else "no changes"
+
+
+class BaseScraper(ABC):
+    """Abstract base class for platform BIOS requirement scrapers."""
+
+    @abstractmethod
+    def fetch_requirements(self) -> list[BiosRequirement]:
+        """Fetch current BIOS requirements from the platform source."""
+        ...
+
+    def compare_with_config(self, config: dict) -> ChangeSet:
+        """Compare scraped requirements against existing platform config."""
+        scraped = self.fetch_requirements()
+        changes = ChangeSet()
+
+        existing = {}
+        for sys_id, system in config.get("systems", {}).items():
+            for f in system.get("files", []):
+                key = (sys_id, f["name"])
+                existing[key] = f
+
+        scraped_map = {}
+        for req in scraped:
+            key = (req.system, req.name)
+            scraped_map[key] = req
+
+        for key, req in scraped_map.items():
+            if key not in existing:
+                changes.added.append(req)
+            else:
+                existing_file = existing[key]
+                if req.sha1 and existing_file.get("sha1") and req.sha1 != existing_file["sha1"]:
+                    changes.modified.append((
+                        BiosRequirement(
+                            name=existing_file["name"],
+                            system=key[0],
+                            sha1=existing_file.get("sha1"),
+                            md5=existing_file.get("md5"),
+                        ),
+                        req,
+                    ))
+                elif req.md5 and existing_file.get("md5") and req.md5 != existing_file["md5"]:
+                    changes.modified.append((
+                        BiosRequirement(
+                            name=existing_file["name"],
+                            system=key[0],
+                            md5=existing_file.get("md5"),
+                        ),
+                        req,
+                    ))
+
+        for key in existing:
+            if key not in scraped_map:
+                f = existing[key]
+                changes.removed.append(BiosRequirement(
+                    name=f["name"],
+                    system=key[0],
+                    sha1=f.get("sha1"),
+                    md5=f.get("md5"),
+                ))
+
+        return changes
+
+    def test_connection(self) -> bool:
+        """Test if the source URL is reachable."""
+        try:
+            self.fetch_requirements()
+            return True
+        except Exception:
+            return False
+
+    @abstractmethod
+    def validate_format(self, raw_data: str) -> bool:
+        """Validate source data format. Returns False if format has changed unexpectedly."""
+        ...
+
+
+def fetch_github_latest_version(repo: str) -> str | None:
+    """Fetch the latest release version tag from a GitHub repo."""
+    url = f"https://api.github.com/repos/{repo}/releases/latest"
+    try:
+        req = urllib.request.Request(url, headers={
+            "User-Agent": "retrobios-scraper/1.0",
+            "Accept": "application/vnd.github.v3+json",
+        })
+        with urllib.request.urlopen(req, timeout=15) as resp:
+            data = json.loads(resp.read())
+            return data.get("tag_name", "")
+    except (urllib.error.URLError, urllib.error.HTTPError, json.JSONDecodeError):
+        return None
+
+
+def fetch_github_latest_tag(repo: str, prefix: str = "") -> str | None:
+    """Fetch the most recent matching tag from a GitHub repo."""
+    url = f"https://api.github.com/repos/{repo}/tags?per_page=50"
+    try:
+        req = urllib.request.Request(url, headers={
+            "User-Agent": "retrobios-scraper/1.0",
+            "Accept": "application/vnd.github.v3+json",
+        })
+        with urllib.request.urlopen(req, timeout=15) as resp:
+            tags = json.loads(resp.read())
+            for tag in tags:
+                name = tag["name"]
+                if prefix and not name.startswith(prefix):
+                    continue
+                return name
+            return tags[0]["name"] if tags else None
+    except (urllib.error.URLError, urllib.error.HTTPError, json.JSONDecodeError):
+        return None