refactor(config): migrar a SettingsConfigDict y quitar Field(env=...)

Elimina las dos deprecaciones de Pydantic V2 (se rompían en V3):
- class Config -> model_config = SettingsConfigDict(env_file='.env')
- Field(env='X') en los 33 campos -> resolución automática por nombre
  de campo (case-insensitive en pydantic-settings); verificado que los
  33 nombres coinciden con su variable, así que el comportamiento es
  idéntico. pytest pasa de 34 warnings a 0.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/config.py

@@ -1,52 +1,51 @@
-from pydantic_settings import BaseSettings
+from pydantic_settings import BaseSettings, SettingsConfigDict
 from pydantic import Field
 from typing import Optional
 
 
 class Settings(BaseSettings):
     # Telegram
-    telegram_bot_token: str = Field(..., env="TELEGRAM_BOT_TOKEN")
+    telegram_bot_token: str = Field(...)
-    telegram_allowed_users: str = Field("", env="TELEGRAM_ALLOWED_USERS")  # comma-separated user IDs
+    telegram_allowed_users: str = Field("")  # comma-separated user IDs
 
     # Ollama
-    ollama_url: str = Field("http://ollama.chemavx.xyz", env="OLLAMA_URL")
+    ollama_url: str = Field("http://ollama.chemavx.xyz")
-    ollama_model: str = Field("qwen2.5:3b", env="OLLAMA_MODEL")
+    ollama_model: str = Field("qwen2.5:3b")
-    ollama_embed_model: str = Field("qwen2.5:3b", env="OLLAMA_EMBED_MODEL")
+    ollama_embed_model: str = Field("qwen2.5:3b")
 
     # Claude fallback (optional)
-    anthropic_api_key: Optional[str] = Field(None, env="ANTHROPIC_API_KEY")
+    anthropic_api_key: Optional[str] = Field(None)
-    claude_model: str = Field("claude-haiku-4-5", env="CLAUDE_MODEL")
+    claude_model: str = Field("claude-haiku-4-5")
 
     # Database
-    db_path: str = Field("/data/researchowl.db", env="DB_PATH")
+    db_path: str = Field("/data/researchowl.db")
 
     # Scraping
-    max_depth: int = Field(3, env="MAX_DEPTH")                      # recursion depth
+    max_depth: int = Field(3)                      # recursion depth
-    max_sources: int = Field(150, env="MAX_SOURCES")                # hard cap
+    max_sources: int = Field(150)                # hard cap
-    max_pages_per_search: int = Field(5, env="MAX_PAGES_PER_SEARCH")
+    max_pages_per_search: int = Field(5)
     searxng_url: str = Field(
         "http://searxng-svc.researchowl.svc.cluster.local:8080/search",
-        env="SEARXNG_URL"
     )
-    request_timeout: int = Field(30, env="REQUEST_TIMEOUT")
+    request_timeout: int = Field(30)
-    request_delay: float = Field(1.0, env="REQUEST_DELAY")          # seconds between requests
+    request_delay: float = Field(1.0)          # seconds between requests
-    min_content_length: int = Field(200, env="MIN_CONTENT_LENGTH")  # chars
+    min_content_length: int = Field(200)  # chars
 
     # Fuentes opcionales — desactivadas por defecto: la IP del homelab está
     # bloqueada por Reddit (403) y YouTube (transcripts vacíos), eran peso muerto.
-    enable_youtube: bool = Field(False, env="ENABLE_YOUTUBE")
+    enable_youtube: bool = Field(False)
-    enable_reddit: bool = Field(False, env="ENABLE_REDDIT")
+    enable_reddit: bool = Field(False)
 
     # Processing
-    chunk_size: int = Field(800, env="CHUNK_SIZE")                  # tokens per chunk
+    chunk_size: int = Field(800)                  # tokens per chunk
-    chunk_overlap: int = Field(100, env="CHUNK_OVERLAP")
+    chunk_overlap: int = Field(100)
-    quality_threshold: float = Field(0.3, env="QUALITY_THRESHOLD")  # 0-1, chunks below discarded
+    quality_threshold: float = Field(0.3)  # 0-1, chunks below discarded
 
     # Ghost CMS
-    ghost_url: Optional[str] = Field(None, env="GHOST_URL")
+    ghost_url: Optional[str] = Field(None)
-    ghost_api_key: Optional[str] = Field(None, env="GHOST_API_KEY")
+    ghost_api_key: Optional[str] = Field(None)
-    ghost_url_en: str = Field("", env="GHOST_URL_EN")
+    ghost_url_en: str = Field("")
-    ghost_api_key_en: str = Field("", env="GHOST_API_KEY_EN")
+    ghost_api_key_en: str = Field("")
 
     # SEO autofill — "off" | "on" | "dryrun" (default off).
     #   off    = today's exact behavior (bare draft, no second LLM call).
@@ -55,28 +54,27 @@ class Settings(BaseSettings):
     #   dryrun = runs the full pipeline + reports the proposed SEO to Telegram, but
     #            writes a BARE draft (no seo fields), for inspection before trusting
     #            the write path. A `/generate blog en dry` arg forces dryrun per-call.
-    seo_autofill: str = Field("off", env="SEO_AUTOFILL")
+    seo_autofill: str = Field("off")
 
     # News monitor (RSS de noticias UAP/OVNI) — inerte hasta NEWS_ENABLED=true.
-    NEWS_ENABLED: bool = Field(False, env="NEWS_ENABLED")
+    NEWS_ENABLED: bool = Field(False)
-    NEWS_POLL_INTERVAL_HOURS: int = Field(6, env="NEWS_POLL_INTERVAL_HOURS")
+    NEWS_POLL_INTERVAL_HOURS: int = Field(6)
     # Chat al que el monitor empuja novedades; si None -> 1er TELEGRAM_ALLOWED_USERS
     # (ver propiedad news_chat_id).
-    NEWS_CHAT_ID: Optional[int] = Field(None, env="NEWS_CHAT_ID")
+    NEWS_CHAT_ID: Optional[int] = Field(None)
     NEWS_KEYWORDS: str = Field(
         "ovni,ovnis,uap,ufo,desclasificado,desclasificacion,declassified,"
         "avistamiento,sighting,extraterrestre,non-human,nhi,grusch,"
         "aaro,pursue,fenomeno aereo,whistleblower",
-        env="NEWS_KEYWORDS",
     )
-    NEWS_MAX_ITEMS: int = Field(15, env="NEWS_MAX_ITEMS")
+    NEWS_MAX_ITEMS: int = Field(15)
 
     # Alerts
-    cost_alert_threshold: float = Field(0.15, env="COST_ALERT_THRESHOLD")
+    cost_alert_threshold: float = Field(0.15)
 
     # App
-    log_level: str = Field("INFO", env="LOG_LEVEL")
+    log_level: str = Field("INFO")
-    timezone: str = Field("Europe/Madrid", env="TIMEZONE")
+    timezone: str = Field("Europe/Madrid")
 
     @property
     def allowed_user_ids(self) -> list[int]:
@@ -102,8 +100,7 @@ class Settings(BaseSettings):
     def seo_autofill_dryrun(self) -> bool:
         return (self.seo_autofill or "").strip().lower() == "dryrun"
 
-    class Config:
+    model_config = SettingsConfigDict(env_file=".env")
-        env_file = ".env"
 
 
 settings = Settings()