feat: production deployment - full update with providers, admin, glossaries, pricing, tests

Major changes across backend, frontend, infrastructure:
- Provider system with model selection (Google, DeepL, OpenAI, Ollama, Google Cloud)
- Admin panel: user management, pricing, settings
- Glossary system with CSV import/export
- Subscription and tier quota management
- Security hardening (rate limiting, API key auth, path traversal fixes)
- Docker compose for dev, prod, and IONOS deployment
- Alembic migrations for new tables
- Frontend: dashboard, pricing page, landing page, i18n (en/fr)
- Test suite and verification scripts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

core/redis.py

@@ -0,0 +1,134 @@
+"""
+Centralized Redis client for the application.
+Single shared async and sync clients; REDIS_URL from environment.
+Used by: rate limiting, tier quota, storage tracker, auth blocklist, admin sessions, health check.
+"""
+from __future__ import annotations
+
+import os
+import logging
+
+logger = logging.getLogger(__name__)
+
+_async_client = None
+_sync_client = None
+# Sentinel: False = no REDIS_URL or connection failed; None = not yet tried
+_async_attempted = None
+_sync_attempted = None
+
+
+def get_redis_url() -> str:
+    """Return REDIS_URL from environment (empty if not set)."""
+    return (os.getenv("REDIS_URL") or "").strip()
+
+
+def get_async_redis():
+    """
+    Return shared async Redis client or None.
+    Uses REDIS_URL from env. Lazy init; on failure returns None (graceful degradation).
+    """
+    global _async_client, _async_attempted
+    if _async_attempted is not None:
+        return _async_client if _async_client is not None else None
+    url = get_redis_url()
+    if not url:
+        _async_attempted = True
+        return None
+    try:
+        import redis.asyncio as redis
+
+        _async_client = redis.Redis.from_url(url, decode_responses=True)
+        logger.info("Redis async client connected (shared)")
+        _async_attempted = True
+        return _async_client
+    except Exception as e:
+        logger.warning("Redis async connection failed: %s", e)
+        _async_client = None
+        _async_attempted = True
+        return None
+
+
+def get_sync_redis():
+    """
+    Return shared sync Redis client or None.
+    Uses REDIS_URL from env. Lazy init; on failure returns None.
+    Used by health check, admin sessions, auth blocklist.
+    """
+    global _sync_client, _sync_attempted
+    if _sync_attempted is not None:
+        return _sync_client if _sync_client is not None else None
+    url = get_redis_url()
+    if not url:
+        _sync_attempted = True
+        return None
+    try:
+        import redis
+
+        _sync_client = redis.Redis.from_url(
+            url, decode_responses=True, socket_connect_timeout=5
+        )
+        _sync_client.ping()
+        logger.info("Redis sync client connected (shared)")
+        _sync_attempted = True
+        return _sync_client
+    except Exception as e:
+        logger.warning("Redis sync connection failed: %s", e)
+        _sync_client = None
+        _sync_attempted = True
+        return None
+
+
+def ping_sync() -> tuple[bool, str]:
+    """
+    Ping Redis (sync). Returns (success, error_message).
+    Use for health/readiness checks.
+    """
+    client = get_sync_redis()
+    if not client:
+        return False, "not_configured"
+    try:
+        client.ping()
+        return True, ""
+    except Exception as e:
+        return False, str(e)
+
+
+# ---------------------------------------------------------------------------
+# Translation job status cache (for GET /api/v1/translations/{id})
+# Key: translation:job:{job_id}, value: JSON, TTL e.g. 2h
+# ---------------------------------------------------------------------------
+
+JOB_STATUS_KEY_PREFIX = "translation:job"
+JOB_STATUS_TTL = 2 * 3600  # 2 hours
+
+
+async def set_job_status_async(job_id: str, data: dict, ttl: int = JOB_STATUS_TTL) -> bool:
+    """Store job status in Redis for multi-instance progress polling. Returns True if stored."""
+    client = get_async_redis()
+    if not client:
+        return False
+    try:
+        import json
+
+        key = f"{JOB_STATUS_KEY_PREFIX}:{job_id}"
+        await client.set(key, json.dumps(data), ex=ttl)
+        return True
+    except Exception as e:
+        logger.warning("Redis set_job_status_async failed for %s: %s", job_id, e)
+        return False
+
+
+async def get_job_status_async(job_id: str) -> dict | None:
+    """Retrieve job status from Redis. Returns None if not found or Redis unavailable."""
+    client = get_async_redis()
+    if not client:
+        return None
+    try:
+        import json
+
+        key = f"{JOB_STATUS_KEY_PREFIX}:{job_id}"
+        data = await client.get(key)
+        return json.loads(data) if data else None
+    except Exception as e:
+        logger.warning("Redis get_job_status_async failed for %s: %s", job_id, e)
+        return None