feat(providers): refresh Qwen3.8 model catalogs

[backryun]

Summary

• replace the retired Qwen3.8 Max Preview identity with qwen3.8-max in the Qwen Web and Qwen Cloud Token Plan catalogs
• add Qwen3.8 Max to Alibaba Model Studio, Qwen Cloud, and the ClinePass offline fallback
• refresh Qwen Cloud Token Plan context/output limits and add DeepSeek V4 Flash
• keep qwen3.8-max-preview working as a Qwen Web compatibility alias while sending the current model ID upstream
• align Qwen Web thinking behavior, free-model metadata, and ordered catalog regression coverage

Live discovery remains authoritative for Qwen Cloud and ClinePass where available. The Qwen Web model ID, 1M context, vision/thinking support, and 131,072-token generation limit were also confirmed against its current public /api/models response.

Validation

• node --import tsx/esm --test tests/unit/clinepass-provider.test.ts — 21/21 passed
• node --import tsx/esm --test tests/unit/alibaba-provider-regions.test.ts tests/unit/executor-qwen-web.test.ts — 27/27 passed
• npm run typecheck:core — passed
• targeted Prettier and ESLint — passed
• Cline public recommended-models endpoint contains cline-pass/qwen3.8-max
• Qwen Web public models endpoint contains qwen3.8-max with the catalog metadata used here

Existing base blockers

• npm run check:provider-consistency reports the pre-existing registry-only chatanywhere entry
• the repository pre-commit docs-sync gate expects ## [Unreleased], while the release base currently starts CHANGELOG.md with ## [3.8.50] — TBD

[diegosouzapw]

Refresh looks good. One check: run check:provider-consistency and confirm the new Qwen3.8 models carry correct pricing/contextLength. Otherwise mergeable.

[backryun]

Re-ran the requested provider consistency check on the exact current head cff2ace: it passes with 260 REGISTRY entries, 340 canonical providers, and 0 exceptions. The Qwen3.8 Max static entries that carry limits use a 1,000,000-token context, while Qwen Web remains keyless with zero-priced free-catalog metadata; live-discovery catalogs remain intentionally minimal. Please take another look when convenient.