Refactor environment and configuration management

- Updated the project structure to store configuration files (.env, models.yaml, extensions.yaml) in the project root instead of the user's home directory.
- Enhanced the setup process to automatically copy example files to the project root on first run.
- Implemented a migration function to transfer legacy configuration files from the user's home directory to the new project structure.
- Revised documentation to reflect changes in file locations and setup instructions.
- Improved code readability and maintainability by refactoring path management functions.

src/gpu_rent/config.py

@@ -1,4 +1,4 @@
-"""Load ~/.gpu-rent/.env. No secrets in git."""
+"""Load <project>/.env. No secrets in git."""
 
 from __future__ import annotations
 
@@ -10,10 +10,13 @@ from dotenv import load_dotenv
 
 from gpu_rent.errors import ConfigError
 from gpu_rent.paths import (
+    app_root,
     default_ssh_key_path,
-    detect_app_root,
     env_path,
-    home_dir,
+    extensions_manifest_path,
+    migrate_legacy_if_needed,
+    models_manifest_path,
+    runtime_dir,
 )
 
 
@@ -96,12 +99,14 @@ def _required(name: str) -> str:
 
 
 def load_config(*, require_auth: bool = True) -> Config:
-    home_dir().mkdir(parents=True, exist_ok=True)
+    root = app_root()
+    runtime_dir().mkdir(parents=True, exist_ok=True)
+    migrate_legacy_if_needed()
+
     env_file = env_path()
     if env_file.is_file():
         load_dotenv(env_file, override=False)
 
-    app_root = detect_app_root()
     missing: list[str] = []
     required = (
         "OS_AUTH_URL",
@@ -119,7 +124,7 @@ def load_config(*, require_auth: bool = True) -> Config:
 
     if require_auth and missing:
         raise ConfigError(
-            "В ~/.gpu-rent/.env не хватает: "
+            f"В {env_file} не хватает: "
             + ", ".join(missing)
             + ". Как заполнить: docs/setup.md (сервисный пользователь, не X-Token)."
         )
@@ -128,16 +133,16 @@ def load_config(*, require_auth: bool = True) -> Config:
     ssh_key = Path(key_override).expanduser() if key_override else default_ssh_key_path()
 
     models_manifest = Path(
-        (os.environ.get("MODELS_MANIFEST") or "").strip() or (home_dir() / "models.yaml")
+        (os.environ.get("MODELS_MANIFEST") or "").strip() or str(models_manifest_path())
     ).expanduser()
     extensions_manifest = Path(
         (os.environ.get("EXTENSIONS_MANIFEST") or "").strip()
-        or (home_dir() / "extensions.yaml")
+        or str(extensions_manifest_path())
     ).expanduser()
 
     def _dir(env_name: str, folder: str) -> Path:
         raw = (os.environ.get(env_name) or "").strip()
-        return Path(raw).expanduser() if raw else (app_root / folder)
+        return Path(raw).expanduser() if raw else (root / folder)
 
     return Config(
         os_auth_url=values["OS_AUTH_URL"] or "https://cloud.api.selcloud.ru/identity/v3",
@@ -162,7 +167,7 @@ def load_config(*, require_auth: bool = True) -> Config:
         local_wildcards_dir=_dir("LOCAL_WILDCARDS_DIR", "Wildcards"),
         local_workflows_dir=_dir("LOCAL_WORKFLOWS_DIR", "CustomWorkflows"),
         local_output_dir=_dir("LOCAL_OUTPUT_DIR", "Output"),
-        app_root=app_root,
+        app_root=root,
         autocomplete_enabled=_as_bool(os.environ.get("AUTOCOMPLETE_ENABLED"), True),
         autocomplete_github_repo=(
             os.environ.get("AUTOCOMPLETE_GITHUB_REPO") or "DominikDoom/a1111-sd-webui-tagcomplete"