赵月辉 / fastgpt-migrated

* feat: support image dataset search

* image recall code

* fix: normalize dataset image inputs

* fix: handle dataset image preview expiry

* update vitest

* fix: track image caption usage metadata

* fix: filter blank embedding queries at callers

* fix: normalize blank dataset search queries

* doc

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Co-authored-by: archer <545436317@qq.com>