Move v1fetch's inline per-target pipeline into a new internal/api/target.go
method, `fetchTarget(ctx, c, t batch.Target) (batch.Result, error)`, so the
batch worker can drive the same work. The body moves unchanged in order:
question truncation, mode default/check, wantCtx, doFetch, the recover path,
the PDF branch (render, pages/grep errors, question-chunk limit), the
clean/raw branch, digest, context search, the fetch log line and the
envelope. `content` is returned as Result.Content; every other envelope key
goes in Result.Meta, never content. v1fetch keeps reqN/caller/decode/400,
builds a batch.Target from the request, calls fetchTarget, writeFetchErr on
error and writeJSON(w, 200, env) on success where env is a copy of Meta plus
"content". doFetch takes context.Context instead of *http.Request; scrape
passes r.Context(). No new behaviour, fields or JSON keys.
Co-Authored-By: ornith-1.5-35b-a3b <ornith-1.5-35b-a3b@llama.cpp.invalid>
kyleandornith-1.5-35b-a3b
0d923bc366