P5a plan: PDF documents — seven Ornith tasks with acceptance tests first

docs/plans/p5a: 01 kind+fetch limits, 02 pdftext child + runner, 03 dcache PDF tables,
04 pdfpool, 05 pdfdoc render (map/pages/grep), 06 api, 07 digest citations, metrics, CLI,
skill, unit, README. Given tests compile against a panic-only skeleton and fail there for the
intended reasons; PDFs for tests are built by internal/pdftest (given), plus two qpdf-encrypted
fixtures.

Owner changes for the run: vendor go-pdfkit/extract v0.3.0 + reader v0.6.0 (pinned via
tools.go until task 02); AGENTS.md, tools/run-plan.sh (enforces a Co-Authored-By trailer for
the model), docs/implementer-log.md, `make gate`; gofmt (whitespace) on clean.go and guard;
TestUnsupportedType uses a zip now that PDFs are supported; requestDeadline 90→210 s and
writeTimeout 120→240 s for the PDF path's worst case.

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

internal/api/api.go

@@ -30,8 +30,8 @@ import (
 
 const (
 	maxReqBody      = 64 << 10
-	writeTimeout    = 120 * time.Second
-	requestDeadline = 90 * time.Second
+	writeTimeout    = 240 * time.Second // P5a: a PDF may take 120 s to download + 20 s queued + 60 s to extract
+	requestDeadline = 210 * time.Second // P5a: the PDF path's worst case (see writeTimeout); other paths keep their own shorter timeouts
 )
 
 type Server struct {