feat(seo): wire autofill into publish path behind SEO_AUTOFILL (default off, dry-run support)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/config.py

@@ -48,6 +48,15 @@ class Settings(BaseSettings):
     ghost_url_en: str = Field("", env="GHOST_URL_EN")
     ghost_api_key_en: str = Field("", env="GHOST_API_KEY_EN")
 
+    # SEO autofill — "off" | "on" | "dryrun" (default off).
+    #   off    = today's exact behavior (bare draft, no second LLM call).
+    #   on     = adds best-effort meta/OG/Twitter/tags/internal-links to the DRAFT
+    #            (status stays "draft" — NEVER auto-publishes; see src/seo/autofill.py).
+    #   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")
+
     # Alerts
     cost_alert_threshold: float = Field(0.15, env="COST_ALERT_THRESHOLD")
 
@@ -61,6 +70,15 @@ class Settings(BaseSettings):
             return []
         return [int(uid.strip()) for uid in self.telegram_allowed_users.split(",") if uid.strip()]
 
+    @property
+    def seo_autofill_enabled(self) -> bool:
+        """True when autofill should run (either live 'on' or 'dryrun')."""
+        return (self.seo_autofill or "").strip().lower() in ("on", "true", "1", "yes", "dryrun")
+
+    @property
+    def seo_autofill_dryrun(self) -> bool:
+        return (self.seo_autofill or "").strip().lower() == "dryrun"
+
     class Config:
         env_file = ".env"