P5a review: outlines from named destinations; pool race; fast over-limit; revalidation under the limiter; Accept pdf

- pdftext/outline: resolve named destinations through the catalog /Dests and the /Names /Dests
  tree, resolve indirect /Dest, /A and /Title, and treat reader.Null (what Dict.Get returns for
  a missing key) as absent. Before this every LaTeX and Acrobat PDF had an empty outline.
  pdftest gains NamedDests; TestOutlineNamedDestinations.
- api: pool() always goes through its Once (data race on concurrent first use);
  TestDefaultPoolConcurrentFirstUse. Revalidation of a stale cache entry counts against the
  caller/host limit.
- pdftext/runner: output over MaxText kills the child at once instead of waiting for the
  deadline; TestRunnerTooMuchTextFailsFast.
- fetch: Accept includes application/pdf;q=0.8.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/pdftext/review_test.go

@@ -0,0 +1,60 @@
+package pdftext_test
+
+// Owner review (P5a): output over MaxText fails fast, not at the deadline. The child writes more
+// than a pipe buffer (64 KiB), so it blocks on stdout until killed; Run must not wait for it to
+// exit on its own before checking the size.
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"testing"
+	"time"
+
+	"git.wntrmute.dev/kyle/sift/internal/pdftest"
+	"git.wntrmute.dev/kyle/sift/internal/pdftext"
+)
+
+func TestRunnerTooMuchTextFailsFast(t *testing.T) {
+	var pages []string
+	for p := 1; p <= 80; p++ {
+		pages = append(pages, pdftest.Lorem(p, 40)) // ~2,700 characters a page, ~200 KiB in all
+	}
+	r := runner()
+	r.MaxText = 1000
+	r.Deadline = 30 * time.Second
+	start := time.Now()
+	_, err := r.Run(context.Background(), pdftest.Build(pdftest.Doc{Pages: pages}))
+	if !errors.Is(err, pdftext.ErrTooMuchText) {
+		t.Fatalf("err %v, want ErrTooMuchText", err)
+	}
+	if d := time.Since(start); d > 5*time.Second {
+		t.Errorf("ErrTooMuchText after %v; it waited for the deadline instead of killing the child", d)
+	}
+}
+
+// Owner review (P5a): LaTeX (hyperref) and Acrobat outlines use named destinations through
+// the /Names tree and indirect titles; the first run returned no outline for any arXiv paper
+// or the NIST PDF. reader's Dict.Get answers reader.Null{} for a missing key, which hid /A.
+func TestOutlineNamedDestinations(t *testing.T) {
+	b := pdftest.Build(pdftest.Doc{
+		Title:      "Named",
+		Pages:      []string{"one", "two", "three"},
+		Outline:    []pdftest.Outline{{Title: "1 Intro", Page: 1, Level: 1}, {Title: "2 Method", Page: 3, Level: 1}},
+		NamedDests: true,
+	})
+	var out bytes.Buffer
+	if err := pdftext.Extract(b, 10, &out); err != nil {
+		t.Fatal(err)
+	}
+	var l struct{ Meta pdftext.Meta }
+	line, _ := out.ReadBytes('\n')
+	if err := json.Unmarshal(line, &l); err != nil {
+		t.Fatal(err)
+	}
+	want := []pdftext.OutlineItem{{Title: "1 Intro", Page: 1, Level: 1}, {Title: "2 Method", Page: 3, Level: 1}}
+	if len(l.Meta.Outline) != 2 || l.Meta.Outline[0] != want[0] || l.Meta.Outline[1] != want[1] {
+		t.Errorf("outline = %+v, want %+v", l.Meta.Outline, want)
+	}
+}