Rename qwen-portal → Qwen Cloud and fix outdated baseUrl #184

Summary

The built-in Qwen Portal preset (qwen-portal) still uses https://portal.qwen.ai/v1, which is outdated. Rename it to Qwen Cloud and point the default at the current pay-as-you-go OpenAI-compatible endpoint.

Current (opencodex)

{ id: "qwen-portal", label: "Qwen Portal", baseUrl: "https://portal.qwen.ai/v1", ... }

Correct endpoints

Do not treat the pay-as-you-go host as a generic regional synonym for other DashScope products, and do not confuse it with Coding Plan / other Alibaba presets.

Suggested fix

1. Rename preset id/label: qwen-portal / “Qwen Portal” → qwen-cloud / “Qwen Cloud”.
2. Set default baseUrl to the pay-as-you-go URL above; update the registry comment accordingly.
3. Document (preset note and/or docs) that token plan uses the separate token-plan.ap-southeast-1… host (existing alibaba-token-plan / user override may apply).
4. Update GUI icon map, docs provider tables, and registry parity tests.
5. Existing saved configs named qwen-portal keep working as custom entries; new installs get qwen-cloud.

Acceptance

• Preset is named Qwen Cloud (qwen-cloud) with pay-as-you-go default baseUrl.
• Comments/docs state pay-as-you-go vs token-plan hosts correctly.
• Docs + icon map + parity tests updated.
• No silent rewrite of users’ existing qwen-portal provider keys.