- Migrated 288 lines of scattered error classification logic from `utils/error-id.ts` into a cohesive `packages/ai/src/error/` module with 13 specialized submodules covering flags, classes, OAuth, providers, rate-limiting, and finalization.
- Replaced 100+ generic `Error` throws across 60+ provider and registry files with semantic `AIError.*` classes (e.g., `AIError.MissingApiKeyError`, `AIError.OAuthError`, `AIError.ProviderResponseError`), improving error diagnostics and retry logic.
- Consolidated error utility imports from `pi-utils` and scattered classification functions into a single `AIError` namespace, reducing coupling and simplifying error handling across all packages.
Prioritized rate-limit wording before auth wording in auth-gateway error classification so DashScope throttling messages that contain unauthorized do not invalidate credentials.
Fixes#3172
- Classified usage-limit gateway responses as `429 rate_limit_error` in auth handling paths.
- Aligned auth-gateway and pi-native key retrieval with derived `sessionId` for `getApiKey` lookups.
- Handled usage-limit auth failures by rotating credentials with retry hints and returning undefined when none available.
- Replaced stream auth checks with retryable-upstream logic for 401 and usage-limit errors before content.
- Expanded `extractRetryHint` parsing for `~`, `sec`, `ms`, and minute/hour units.
- Added coverage for classifyGatewayError, retry-hint parsing variants, and stream-auth retry edge cases.
- Added optional `name` support to tool message schema, coercing blank values to undefined.
- Tracked assistant tool-call IDs to resolve `tool` message names from prior calls when wire names are missing.
- Updated auth-gateway classification to prefer explicit/embedded status codes over text heuristics.
- Added word-boundary matching, expanded parse/error tests, and updated changelog entries.
can1357