GitLab

- Fix errcheck: brave.go resp.Body.Close, manager_test.go Encode
- Fix gofmt: payment_config_service.go
- Fix unused: use shouldFallbackGeminiModel (with modelName param) in handler

- Fix errcheck: handle Write/Encode return values in brave_test.go
- Fix errcheck: defer resp.Body.Close() with _ assignment in tavily.go
- Fix gofmt: payment.go, channel.go, payment_config_providers.go
- Fix unused: remove dead decodeURLValue in easypay.go
- Restore shouldFallbackGeminiModel function (deleted during cherry-pick)
- Add missing balanceNotifyService param to NewGatewayService in test
- Fix platform default test expectation (empty stays empty)
- Fix wildcard pricing test (longest prefix wins, not config order)
- Fix subscription group test (SUBSCRIPTION_REPOSITORY_UNAVAILABLE)

Billing (25 tests):
- CalculateCostUnified: nil resolver fallback, token/per_request/image modes
- GetModelPricingWithChannel: nil/partial/full channel overrides
- resolveAccountStatsCost: four-level priority chain integration tests

WebSearch (18 tests):
- PopulateWebSearchUsage: nil input, manager states, QuotaLimit nil/*int64
- ResetWebSearchUsage: nil manager error
- Manager.ResetUsage: nil Redis
- shouldEmulateWebSearch: full decision chain (8 scenarios)

Notify (36 tests):
- ParseNotifyEmails/MarshalNotifyEmails: old/new format, roundtrip
- crossedDownward: boundary values, threshold semantics
- checkQuotaDimCrossings: mixed dimensions, disabled/zero skip

- QuotaLimit changed to *int64 (null=unlimited, >0=limited)
- Add reset-usage endpoint (POST /admin/settings/web-search-emulation/reset-usage)
- Show quota usage in header always (collapsed and expanded)
- Add reset quota button in expanded provider view
- Quota input: empty=unlimited with ∞ placeholder, must be >0 if set
- Add email verification hint on balance notify card

- Skip websearch provider when ProxyID is set but proxy not found (prevent
  silent direct connection bypass)
- Fix sortByStableRandomWeight: pair factors with items so sort.Slice swap
  keeps weights aligned
- Allow empty platform in account_stats_pricing_rules (wildcard matching),
  only force anthropic default for main model_pricing
- Add channel_account_stats_pricing_intervals table and repo layer support
  for interval-based pricing in account stats rules
- calculateTokenStatsCost now uses interval pricing when available
- Replace smtp.SendMail/tls.Dial with net.Dialer timeout (10s dial, 20s IO)
  to prevent goroutine leak on SMTP hang
- Fix gofmt formatting issues
- Web Search label: black text with red warning hint

- Fix websearch provider failover: proxy error from provider-specific proxy
  now continues to next provider instead of aborting the entire loop
- Fix SMTP failure locking users out: send email first, then write cache
  and increment rate counter
- Fix notify email cache key case sensitivity: normalize to lowercase
- Add OriginalPrice validation to validatePlanPatch and validatePlanRequired
- Add empty scope validation for channel pricing rules (group_ids/account_ids)
- Add platform color to account search dropdown in channel pricing rules

- Remove Priority field, auto load-balance by quota remaining
- Replace QuotaRefreshInterval (daily/weekly/monthly) with SubscribedAt
  (subscription date, monthly lazy refresh via Redis TTL)
- Add collapsible provider cards, API key show/copy, usage progress bar
- Add test endpoint (POST /web-search-emulation/test) bypassing quota
- Wire WebSearchManagerBuilder on startup (was never called before)
- Fix nextMonthlyReset day-of-month overflow (Jan 31 → Feb 28)
- Fix non-deterministic sort in selectByQuotaWeight
- Map ProxyID in builder for provider-level proxy tracking
- Fix frontend timezone drift in subscribed_at date picker
- Fix provider deletion index shift for expandedProviders state

- Add TLS error detection to isProxyError (RecordHeaderError, handshake)
- Case-insensitive error string matching
- Add 19 unit tests for: isProviderAvailable, resolveProxyID,
  isProxyError, isProxyAvailable, selectByQuotaWeight, newHTTPClient

- Use proxyutil.ConfigureTransportProxy for unified proxy protocol support
  (HTTP/HTTPS/SOCKS5/SOCKS5H), replacing ad-hoc HTTP-only proxy code
- Proxy errors return ErrProxyUnavailable → gateway triggers account switch
  via UpstreamFailoverError instead of fallback to direct connection
- Timeout: proxy dial 3s, TLS handshake 3s, data transfer 60s
- Mark proxy unavailable for 5 minutes in Redis on connectivity failure
- Quota-weighted load balancing: providers with quota_limit>0 are selected
  by remaining quota (weighted random); quota_limit=0 providers treated as
  0% weight and placed last

Inject web search capability for Claude Console (API Key) accounts that
don't natively support Anthropic's web_search tool. When a pure
web_search request is detected, the gateway calls Brave Search or Tavily
API directly and constructs an Anthropic-protocol-compliant SSE/JSON
response without forwarding to upstream.

Backend:
- New `pkg/websearch/` SDK: Brave and Tavily provider implementations
  with io.LimitReader, proxy support, and Redis-based quota tracking
  (Lua atomic INCR + TTL, DECR rollback on failure)
- Global config via `settings.web_search_emulation_config` (JSON) with
  in-process cache + singleflight, input validation, API key merge on
  save, and sanitized API responses
- Channel-level toggle via `channels.features_config` JSONB column
  (DB migration 101)
- Account-level toggle via `accounts.extra.web_search_emulation`
- Request interception in `Forward()` with SSE streaming response
  construction using json.Marshal (no manual string concatenation)
- Manager hot-reload: `RebuildWebSearchManager()` called on config save
  and startup via `SetWebSearchRedisClient()`
- 70 unit tests covering providers, manager, config validation,
  sanitization, tool detection, query extraction, and response building

Frontend:
- Settings → Gateway tab: Web Search Emulation config card with global
  toggle, provider list (add/remove, API key, priority, quota, proxy)
- Channels → Anthropic tab: web search emulation toggle with global
  state linkage (disabled when global off)
- Account Create/Edit modals: web search emulation toggle for API Key
  type with Toggle component
- Full i18n coverage (zh + en)