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/paths.py

@@ -1,33 +1,91 @@
-"""Paths: ~/.gpu-rent, app tree, SSH key."""
+"""Paths: project root, local .gpu-rent runtime, SSH key."""
 
 from __future__ import annotations
 
+import shutil
 from pathlib import Path
 
 
-def home_dir() -> Path:
-    return Path.home() / ".gpu-rent"
-
-
-def env_path() -> Path:
-    return home_dir() / ".env"
-
-
-def state_path() -> Path:
-    return home_dir() / "state.json"
-
-
-def lock_path() -> Path:
-    return home_dir() / "gpu-rent.lock"
-
-
-def default_ssh_key_path() -> Path:
-    return home_dir() / "id_ed25519"
-
-
 def detect_app_root() -> Path:
     cwd = Path.cwd().resolve()
     for candidate in (cwd, *cwd.parents):
         if (candidate / "Models").is_dir() and (candidate / "docs").is_dir():
             return candidate
     return cwd
+
+
+def app_root() -> Path:
+    return detect_app_root()
+
+
+def runtime_dir() -> Path:
+    """State, lock, SSH key — always inside the project (gitignored)."""
+    return app_root() / ".gpu-rent"
+
+
+# Back-compat alias used across the package.
+def home_dir() -> Path:
+    return runtime_dir()
+
+
+def env_path() -> Path:
+    return app_root() / ".env"
+
+
+def models_manifest_path() -> Path:
+    return app_root() / "models.yaml"
+
+
+def extensions_manifest_path() -> Path:
+    return app_root() / "extensions.yaml"
+
+
+def state_path() -> Path:
+    return runtime_dir() / "state.json"
+
+
+def lock_path() -> Path:
+    return runtime_dir() / "gpu-rent.lock"
+
+
+def default_ssh_key_path() -> Path:
+    return runtime_dir() / "id_ed25519"
+
+
+def legacy_user_dir() -> Path:
+    """Old location (~/.gpu-rent) — only for one-shot migrate."""
+    return Path.home() / ".gpu-rent"
+
+
+def migrate_legacy_if_needed() -> list[str]:
+    """Copy ~/.gpu-rent leftovers into the project once. Returns log lines."""
+    legacy = legacy_user_dir()
+    if not legacy.is_dir():
+        return []
+    root = app_root()
+    runtime = runtime_dir()
+    notes: list[str] = []
+
+    pairs = (
+        (legacy / ".env", env_path()),
+        (legacy / "models.yaml", models_manifest_path()),
+        (legacy / "extensions.yaml", extensions_manifest_path()),
+        (legacy / "state.json", state_path()),
+        (legacy / "id_ed25519", default_ssh_key_path()),
+        (legacy / "id_ed25519.pub", default_ssh_key_path().with_suffix(".pub")),
+    )
+    for src, dst in pairs:
+        if not src.is_file() or dst.is_file():
+            continue
+        dst.parent.mkdir(parents=True, exist_ok=True)
+        shutil.copy2(src, dst)
+        notes.append(f"перенёс {src} → {dst}")
+    if notes:
+        runtime.mkdir(parents=True, exist_ok=True)
+        marker = runtime / ".migrated-from-user-home"
+        if not marker.is_file():
+            marker.write_text(
+                f"from {legacy}\n" + "\n".join(notes) + "\n",
+                encoding="utf-8",
+            )
+    return notes