Add a new /api/user/channels endpoint that returns only enabled channels
with non-sensitive fields (id, name, type, remark) for token channel binding.
Update EditTokenModal to use this endpoint and display remark instead of ID
in the channel dropdown.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Rename "输入倍率" to "模型倍率" for model_ratio field
- Rename "输出倍率" to "补全倍率" for completion_ratio field
- Update help text to reflect accurate pricing calculation
- Add search functionality for model filtering
- Improve table expansion behavior
- Fix channel data loading in ModelSettingsVisualEditor
- Conditionally show ratio/price fields based on quota type

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Add bound_channel_id field to EditTokenModal for channel binding
- Load channels list for dropdown selection
- Add i18n translations for channel pricing features (zh-CN, en)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Add view mode switch (global vs channel) to ModelSettingsVisualEditor
- Create ChannelPricingView component for channel-specific pricing
- Add pricing tag management tab to RatioSetting

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>