feat: add EN/ES/RO language selector for AI pitch generation

- db.py: add `language` column to ai_queue; migration; queue_ai() accepts
  language param and re-queues with ON CONFLICT UPDATE so changing language works
- main.py: batch and single assess endpoints accept `language` from request body
- enricher.py: ai_worker_loop reads language column, passes to _assess_one()
- replicate_ai.py: assess_domain() and _build_prompt() accept language param;
  OUTPUT LANGUAGE section injected into prompt so Gemini writes pitch/email in
  the requested language (EN/ES/RO)
- index.html: flag dropdown (🇪🇸/🇬🇧/🇷🇴) next to AI Assess button; aiLang
  state default ES; language sent in all batch assessment requests

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

app/enricher.py

@@ -328,19 +328,19 @@ async def worker_loop():
 
 # ── AI assessment worker ──────────────────────────────────────────────────────
 
-async def _assess_one(domain: str) -> None:
+async def _assess_one(domain: str, language: str = "ES") -> None:
     """Process a single AI assessment — safe to call concurrently."""
     from app.replicate_ai import assess_domain as gemini_assess
     from app.site_analyzer import analyze_site
 
-    logger.info("AI: starting analysis for %s", domain)
+    logger.info("AI: starting analysis for %s (lang=%s)", domain, language)
     try:
         # Hard 3-minute ceiling so stuck jobs never block the worker forever
         async with asyncio.timeout(180):
             analysis = await analyze_site(domain)
             logger.info("AI: site analyzed %s (reachable=%s, words=%s)",
                         domain, analysis.get("reachable"), analysis.get("word_count"))
-            assessment = await gemini_assess(analysis)
+            assessment = await gemini_assess(analysis, language=language)
             logger.info("AI: Gemini done %s → quality=%s",
                         domain, assessment.get("lead_quality"))
             await save_ai_assessment(domain, assessment, site_analysis=analysis)
@@ -377,7 +377,7 @@ async def ai_worker_loop():
         try:
             async with aiosqlite.connect(SQLITE_PATH) as db:
                 async with db.execute(
-                    "SELECT domain FROM ai_queue WHERE status='pending' LIMIT 5"
+                    "SELECT domain, COALESCE(language,'ES') FROM ai_queue WHERE status='pending' LIMIT 5"
                 ) as cur:
                     rows = await cur.fetchall()
                 if rows:
@@ -399,7 +399,7 @@ async def ai_worker_loop():
 
         # Run assessments concurrently (semaphore in replicate_ai enforces AI_CONCURRENCY)
         results = await asyncio.gather(
-            *[_assess_one(r[0]) for r in rows],
+            *[_assess_one(r[0], r[1]) for r in rows],
             return_exceptions=True,
         )
         for r, exc in zip(rows, results):