fix(install): 安装向导 Redis 密码不被 nx update/Compose 覆盖

Compose 不再注入 NEXUS_REDIS_URL；nx update 保留卷内带密码 URL；步骤 4 可从 install state 修复无密码 URL。

Co-authored-by: Cursor <cursoragent@cursor.com>

server/api/install.py

@@ -408,6 +408,27 @@ def _init_db_request_from_redis_url(redis_url: str) -> InitDbRequest | None:
     )
 
 
+def _redis_repair_request(redis_url: str) -> InitDbRequest | None:
+    """Build InitDbRequest for connection-check repair (URL + install state password)."""
+    req = _init_db_request_from_redis_url(redis_url)
+    if not req:
+        return None
+    if (req.redis_pass or "").strip():
+        return req
+    if not STATE_FILE.is_file():
+        return req
+    import json
+
+    try:
+        state = json.loads(read_utf8_text(STATE_FILE))
+    except (json.JSONDecodeError, OSError):
+        return req
+    saved_pass = (state.get("redis_pass") or "").strip()
+    if saved_pass:
+        return req.model_copy(update={"redis_pass": saved_pass})
+    return req
+
+
 def _mask_redis_url(redis_url: str) -> str:
     parsed = urlparse(redis_url)
     if not parsed.password:
@@ -957,7 +978,7 @@ async def connection_check():
     resolved_display: str | None = None
 
     if not redis_ok and redis_url:
-        req_from_env = _init_db_request_from_redis_url(redis_url)
+        req_from_env = _redis_repair_request(redis_url)
         if req_from_env:
             ok, msg, resolved = _resolve_redis_url(_sanitize_redis_request(req_from_env))
             if ok and resolved:
@@ -1124,6 +1145,11 @@ async def init_db(req: InitDbRequest):
         "install_dir": install_dir,
         "site_url": site_url,
         "api_port": req.api_port,
+        "redis_host": req.redis_host,
+        "redis_port": req.redis_port,
+        "redis_db": req.redis_db,
+        # Step 4 connection-check repair only; removed when install locks
+        "redis_pass": req.redis_pass,
         "guardian_results": guardian_results,
         "docker_mode": _is_docker_install_mode(),
         "step": 4,