feat(config): add YAML config and graceful pagination timeout

fixes #17, fixes #18

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/gitea_dashboard/config.py

@@ -0,0 +1,112 @@
+"""Configuration YAML pour gitea-dashboard."""
+
+from __future__ import annotations
+
+import os
+import re
+from pathlib import Path
+from typing import Any
+
+import yaml
+
+_DEFAULT_CONFIG_PATHS = [
+    Path(".gitea-dashboard.yml"),
+    Path.home() / ".config" / "gitea-dashboard" / "config.yml",
+]
+
+_ENV_VAR_RE = re.compile(r"\$\{([^}]+)\}")
+
+
+def resolve_env_vars(value: str) -> str:
+    """Resout les references ${VAR} dans une valeur string.
+
+    Remplace ${VAR} par os.environ[VAR].
+    Si VAR n'est pas defini, laisse la reference telle quelle.
+    Ne resout pas les references imbriquees.
+    """
+
+    def _replace(match: re.Match) -> str:
+        var_name = match.group(1)
+        return os.environ.get(var_name, match.group(0))
+
+    return _ENV_VAR_RE.sub(_replace, value)
+
+
+def _resolve_values(data: Any) -> Any:
+    """Resout recursivement les ${VAR} dans les valeurs string et listes."""
+    if isinstance(data, str):
+        return resolve_env_vars(data)
+    if isinstance(data, list):
+        return [_resolve_values(item) for item in data]
+    if isinstance(data, dict):
+        return {k: _resolve_values(v) for k, v in data.items()}
+    return data
+
+
+def load_config(config_path: str | None = None) -> dict[str, Any]:
+    """Charge la configuration depuis un fichier YAML.
+
+    Ordre de recherche si config_path est None :
+    1. .gitea-dashboard.yml (repertoire courant)
+    2. ~/.config/gitea-dashboard/config.yml
+
+    Retourne un dict vide si aucun fichier trouve.
+    Leve FileNotFoundError si config_path est fourni mais n'existe pas.
+    Leve ValueError si le YAML est syntaxiquement invalide.
+    """
+    if config_path is not None:
+        path = Path(config_path)
+        if not path.exists():
+            msg = f"Config file not found: {config_path}"
+            raise FileNotFoundError(msg)
+        return _load_yaml_file(path)
+
+    for path in _DEFAULT_CONFIG_PATHS:
+        if path.exists():
+            return _load_yaml_file(path)
+
+    return {}
+
+
+def _load_yaml_file(path: Path) -> dict[str, Any]:
+    """Charge et parse un fichier YAML avec resolution des variables."""
+    try:
+        raw = yaml.safe_load(path.read_text(encoding="utf-8"))
+    except yaml.YAMLError as exc:
+        msg = f"Invalid YAML in {path}: {exc}"
+        raise ValueError(msg) from exc
+
+    if raw is None:
+        return {}
+    if not isinstance(raw, dict):
+        msg = f"Invalid config format in {path}: expected a mapping, got {type(raw).__name__}"
+        raise ValueError(msg)
+
+    return _resolve_values(raw)
+
+
+def merge_config(
+    cli_args: dict[str, Any],
+    env_vars: dict[str, Any],
+    file_config: dict[str, Any],
+    defaults: dict[str, Any],
+) -> dict[str, Any]:
+    """Fusionne les sources de configuration par priorite.
+
+    Priorite : cli_args > env_vars > file_config > defaults.
+    Une valeur None dans une source de priorite superieure ne masque pas
+    la valeur d'une source de priorite inferieure.
+    """
+    all_keys = set()
+    for source in (cli_args, env_vars, file_config, defaults):
+        all_keys.update(source.keys())
+
+    result: dict[str, Any] = {}
+    for key in all_keys:
+        for source in (cli_args, env_vars, file_config, defaults):
+            value = source.get(key)
+            if value is not None:
+                result[key] = value
+                break
+
+    return result