fix(modpack-checker): Code review fixes — license, safety, and polish

Fixes 10 issues from full code review:
- License corrected from MIT to Commercial
- Deprecated datetime.utcnow() replaced with timezone-aware alternative
- PHP array bounds checks added for all platform API responses
- Modrinth file detection now derives project slug instead of using MC version
- validate_api_key() no longer swallows network errors
- HTTP timeouts added to all external API calls in PHP
- Empty API key rejection added to CLI
- Corrupted config now warns on stderr instead of failing silently
- Error response format made consistent across controller
- Docs updated with correct repo URL and clearer CurseForge ID instructions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

services/modpack-version-checker/src/modpack_checker/cli.py

@@ -80,8 +80,12 @@ def config_group() -> None:
 @click.argument("api_key")
 def config_set_key(api_key: str) -> None:
     """Save your CurseForge API key and validate it."""
+    api_key = api_key.strip()
+    if not api_key:
+        console.print("[red]Error:[/red] API key cannot be empty.")
+        sys.exit(1)
     cfg = Config.load()
-    cfg.curseforge_api_key = api_key.strip()
+    cfg.curseforge_api_key = api_key
     cfg.save()
 
     client = CurseForgeClient(api_key)

services/modpack-version-checker/src/modpack_checker/config.py

@@ -31,7 +31,11 @@ class Config(BaseModel):
                     data = json.load(f)
                 return cls(**data)
             except (json.JSONDecodeError, ValueError):
-                # Corrupted config — fall back to defaults silently
+                import sys
+                print(
+                    f"Warning: config file corrupted ({CONFIG_FILE}), using defaults.",
+                    file=sys.stderr,
+                )
                 return cls()
         return cls()
 

services/modpack-version-checker/src/modpack_checker/curseforge.py

@@ -130,7 +130,7 @@ class CurseForgeClient:
         try:
             self._get(f"/v1/games/{self._MINECRAFT_GAME_ID}")
             return True
-        except (CurseForgeAuthError, CurseForgeError):
+        except CurseForgeAuthError:
             return False
 
     def get_mod(self, mod_id: int) -> Dict[str, Any]:

services/modpack-version-checker/src/modpack_checker/database.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from datetime import datetime
+from datetime import datetime, timezone
 from pathlib import Path
 from typing import List, Optional
 
@@ -164,11 +164,11 @@ class Database:
             if row is None:
                 raise ValueError(f"Modpack {curseforge_id} not found in database.")
             row.current_version = version
-            row.last_checked = datetime.utcnow()
+            row.last_checked = datetime.now(timezone.utc)
             session.add(
                 _CheckHistoryRow(
                     modpack_id=row.id,
-                    checked_at=datetime.utcnow(),
+                    checked_at=datetime.now(timezone.utc),
                     version_found=version,
                     notification_sent=notification_sent,
                 )