phsl / new-api

- log_info_generate.go: add nil guard in InjectTieredBillingInfo
- billing_expr_request.go: merge headers instead of replacing
- go.mod: remove incorrect // indirect on expr-lang/expr
- ToolPriceSettings.jsx: add null check in syncToVisual
- tool_billing.go: fix PricePer1K for image_generation (per-call, not per-1K)
- utils.jsx: add minute() to time condition regex
- useUsageLogsData.jsx: pass displayMode to renderTieredModelPrice
- AGENTS.md, CLAUDE.md: fix Rule 6/7 ordering
- relay-gemini.go: add TEXT modality case in CandidatesTokensDetails