chore: remove leftover Sora references after platform removal

PR #1463 removed the Sora platform, but some references survived:

- README/README_CN/README_JA kept the 'Sora status (temporarily
  unavailable)' sections and gateway.sora_* docs that the removal PR
  never touched.
- deploy/config.example.yaml still documented ~130 lines of sora_*
  gateway keys, the top-level sora: direct-client/storage block, and
  token_refresh.sync_linked_sora_accounts - none of which map to any
  field in the config structs anymore.
- The OIDC login PR (02a66a01c, branched off pre-removal main and
  merged 4 days after #1463) re-added the dead
  PublicSettings.SoraClientEnabled field, which no code ever sets.
- A release sync (748a84d87) re-introduced sora i18n keys that the
  later i18n split (d9e514f98) faithfully carried into
  locales/{zh,en}/admin/{overview,settings}.ts. No component references
  any of these keys.

This drops all of the above. Pure deletions, no behavior change.

deploy/config.example.yaml

@@ -228,33 +228,6 @@ gateway:
   # Enable Gemini upstream response header debug logs (default: false)
   # 是否开启 Gemini 上游响应头调试日志（默认 false）
   gemini_debug_response_headers: false
-  # Sora max request body size in bytes (0=use max_body_size)
-  # Sora 请求体最大字节数（0=使用 max_body_size）
-  sora_max_body_size: 268435456
-  # Sora stream timeout (seconds, 0=disable)
-  # Sora 流式请求总超时（秒，0=禁用）
-  sora_stream_timeout_seconds: 900
-  # Sora non-stream timeout (seconds, 0=disable)
-  # Sora 非流式请求超时（秒，0=禁用）
-  sora_request_timeout_seconds: 180
-  # Sora stream enforcement mode: force/error
-  # Sora stream 强制策略：force/error
-  sora_stream_mode: "force"
-  # Sora model filters
-  # Sora 模型过滤配置
-  sora_model_filters:
-    # Hide prompt-enhance models by default
-    # 默认隐藏 prompt-enhance 模型
-    hide_prompt_enhance: true
-  # Require API key for /sora/media proxy (default: false)
-  # /sora/media 是否强制要求 API Key（默认 true）
-  sora_media_require_api_key: true
-  # Sora media temporary signing key (empty disables signed URL)
-  # Sora 媒体临时签名密钥（为空则禁用签名）
-  sora_media_signing_key: ""
-  # Signed URL TTL seconds (<=0 disables)
-  # 临时签名 URL 有效期（秒，<=0 表示禁用）
-  sora_media_signed_url_ttl_seconds: 900
   # Connection pool isolation strategy:
   # 连接池隔离策略：
   # - proxy: Isolate by proxy, same proxy shares connection pool (suitable for few proxies, many accounts)
@@ -649,112 +622,9 @@ log:
     # 之后每 N 条保留 1 条
     thereafter: 100
 
-# =============================================================================
-# Sora Direct Client Configuration
-# Sora 直连配置
-# =============================================================================
-sora:
-  client:
-    # Sora backend base URL
-    # Sora 上游 Base URL
-    base_url: "https://sora.chatgpt.com/backend"
-    # Request timeout (seconds)
-    # 请求超时（秒）
-    timeout_seconds: 120
-    # Max retries for upstream requests
-    # 上游请求最大重试次数
-    max_retries: 3
-    # Account+proxy cooldown window after Cloudflare challenge (seconds, 0 to disable)
-    # Cloudflare challenge 后按账号+代理冷却窗口（秒，0 表示关闭）
-    cloudflare_challenge_cooldown_seconds: 900
-    # Poll interval (seconds)
-    # 轮询间隔（秒）
-    poll_interval_seconds: 2
-    # Max poll attempts
-    # 最大轮询次数
-    max_poll_attempts: 600
-    # Recent task query limit (image)
-    # 最近任务查询数量（图片轮询）
-    recent_task_limit: 50
-    # Recent task query max limit (fallback)
-    # 最近任务查询最大数量（回退）
-    recent_task_limit_max: 200
-    # Enable debug logs for Sora upstream requests
-    # 启用 Sora 直连调试日志
-    # 调试日志会输出上游请求尝试、重试、响应摘要；Authorization/openai-sentinel-token 等敏感头会自动脱敏
-    debug: false
-    # Allow Sora client to fetch token via OpenAI token provider
-    # 是否允许 Sora 客户端通过 OpenAI token provider 取 token（默认 false，避免误走 OpenAI 刷新链路）
-    use_openai_token_provider: false
-    # Optional custom headers (key-value)
-    # 额外请求头（键值对）
-    headers: {}
-    # Default User-Agent for Sora requests
-    # Sora 默认 User-Agent
-    user_agent: "Sora/1.2026.007 (Android 15; 24122RKC7C; build 2600700)"
-    # Disable TLS fingerprint for Sora upstream
-    # 关闭 Sora 上游 TLS 指纹伪装
-    disable_tls_fingerprint: false
-    # curl_cffi sidecar for Sora only (required)
-    # 仅 Sora 链路使用的 curl_cffi sidecar（必需）
-    curl_cffi_sidecar:
-      # Sora 强制通过 sidecar 请求，必须启用
-      # Sora is forced to use sidecar only; keep enabled=true
-      enabled: true
-      # Sidecar base URL (default endpoint: /request)
-      # sidecar 基础地址（默认请求端点：/request）
-      base_url: "http://sora-curl-cffi-sidecar:8080"
-      # curl_cffi impersonate profile, e.g. chrome131/chrome124/safari18_0
-      # curl_cffi 指纹伪装 profile，例如 chrome131/chrome124/safari18_0
-      impersonate: "chrome131"
-      # Sidecar request timeout (seconds)
-      # sidecar 请求超时（秒）
-      timeout_seconds: 60
-      # Reuse session key per account+proxy to let sidecar persist cookies/session
-      # 按账号+代理复用 session key，让 sidecar 持久化 cookies/session
-      session_reuse_enabled: true
-      # Session TTL in sidecar (seconds)
-      # sidecar 会话 TTL（秒）
-      session_ttl_seconds: 3600
-  storage:
-    # Storage type (local only for now)
-    # 存储类型（首发仅支持 local）
-    type: "local"
-    # Local base path; empty uses /app/data/sora
-    # 本地存储基础路径；为空使用 /app/data/sora
-    local_path: ""
-    # Fallback to upstream URL when download fails
-    # 下载失败时回退到上游 URL
-    fallback_to_upstream: true
-    # Max concurrent downloads
-    # 并发下载上限
-    max_concurrent_downloads: 4
-    # Download timeout (seconds)
-    # 下载超时（秒）
-    download_timeout_seconds: 120
-    # Max download bytes
-    # 最大下载字节数
-    max_download_bytes: 209715200
-    # Enable debug logs for media storage
-    # 启用媒体存储调试日志
-    debug: false
-    cleanup:
-      # Enable cleanup task
-      # 启用清理任务
-      enabled: true
-      # Retention days
-      # 保留天数
-      retention_days: 7
-      # Cron schedule
-      # Cron 调度表达式
-      schedule: "0 3 * * *"
-
 # Token refresh behavior
 # token 刷新行为控制
 token_refresh:
-  # Whether OpenAI refresh flow is allowed to sync linked Sora accounts
-  # 是否允许 OpenAI 刷新流程同步覆盖 linked_openai_account_id 关联的 Sora 账号 token
-  sync_linked_sora_accounts: false
   # Candidate accounts loaded per cursor page (maximum 1000)
   # 每个游标分页加载的候选账号数量（最大 1000）
   candidate_page_size: 200