feat: add initial uipath explainator implementation

Scaffold project with pyproject.toml and environment configuration
Implement core modules including CLI, Gemini integration, and scanner

src/uipath_explainator/config.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Self
+
+from dotenv import load_dotenv
+import os
+
+
+@dataclass(slots=True)
+class Settings:
+    api_key: str | None
+    base_url: str | None
+    model: str
+
+    @classmethod
+    def from_env(cls, env_file: Path | None = None, model_override: str | None = None) -> Self:
+        if env_file:
+            load_dotenv(env_file)
+        else:
+            load_dotenv()
+
+        return cls(
+            api_key=os.getenv("GEMINI_API_KEY") or os.getenv("GOOGLE_API_KEY"),
+            base_url=os.getenv("GEMINI_BASE_URL") or None,
+            model=model_override or os.getenv("GEMINI_MODEL") or "gemini-2.5-flash",
+        )
+
+    def require_api_key(self) -> None:
+        if not self.api_key:
+            raise ValueError("Missing GEMINI_API_KEY (or GOOGLE_API_KEY) in the environment.")