Move process wiring, technical adapters, and cross-cutting contracts out of flat internal/ packages so new code has a clear home without changing business layout.
Introduce upload/ingest as the single domain entry for storing files,
writing w_uploads records, and maintaining incremental stats. Refactor
HTTP UploadFile and delete handlers to delegate to ingest, fix stats
decrement ordering on Remove, and document usage in the file-upload skill.
Replace c.JSON(200, response.Err) and middleware gin.H bypasses with
response.Abort* helpers so errors flow through Gin Error chain and
ErrorHandlerMiddleware for OTel trace correlation.
Split oauth/sources.go into domain-focused files and decompose upload
into handler/filesrv/stats/task/cache/storage/util subpackages with a
root facade preserving existing import paths.