GitLab

Backend fixes:
- Fix balance notify ignoring percentage threshold type (was treating
  percentage value as fixed USD amount)
- Remove dead code parseJSONStringArray
- Add ImageOutputTokens to tryModelFilePricing calculation
- Unify zero-value check: cost == 0 → cost <= 0 in calculateTokenStatsCost
- Use MarshalNotifyEmails instead of json.Marshal for consistency
- Rename quotaDim.oldUsed → currentUsed for clarity
- Extract HTML email templates to const variables (function ≤30 lines)

Test fixes:
- Rewrite account_websearch_test.go for GetWebSearchEmulationMode tri-state
- Add 6 tryModelFilePricing test cases

Frontend fixes:
- Replace hardcoded '未命名' with i18n key
- Extract getBillingModeLabel/getBillingModeBadgeClass to shared utils
- Replace inline type with imported NotifyEmailEntry
- Pass platform to AccountStats pricing rules via inferRulePlatform()
- Add billing mode constants (BILLING_MODE_TOKEN/PER_REQUEST/IMAGE)

Allow channels to configure independent model pricing for account
statistics cost calculation, decoupled from user billing.

Backend:
- Migration 101: channels.apply_pricing_to_account_stats toggle,
  channel_account_stats_pricing_rules/model_pricing tables,
  usage_logs.account_stats_cost column
- resolveAccountStatsCost: match rules by group/account, then channel
  pricing, fallback to original formula when unconfigured
- Integrate into both GatewayService.recordUsageCore and
  OpenAIGatewayService.RecordUsage
- Update 8 account stats SQL queries to use
  COALESCE(account_stats_cost, total_cost) * account_rate_multiplier
- 23 unit tests for matching, pricing lookup, and cost calculation

Frontend:
- Channel edit dialog: toggle + custom rules UI with group/account
  multi-select and pricing entry cards
- API types and i18n (zh/en)