fix: bound PDF text extraction and recover parser panics in intake [sec-check]

[hivecommons-hive]

Security Fix

Files/functions claimed: pkg/intake/intake.go (ExtractPDF), pkg/intake/intake_test.go (new malformed/multi-page PDF tests).

ExtractPDF handed the whole upload to pdf.Reader.GetPlainText(), which materializes every page's decompressed text into a single buffer before returning. PDF content streams are FlateDecode-compressed, so a crafted PDF within the 25 MB upload cap can expand ~1000:1 into multi-GB allocations — an OOM DoS reachable by any signed-in user via POST /api/intake. The reader-level parser entry points (NewReader/NumPage/Page) also panic on malformed input, and ExtractPDF had no recover.

This change:

• extracts page by page, accumulating through the existing writeLimitedRunes helper and stopping at extractRunesLimit (20 001 runes) — the caller only ever returns MaxReturnedRunes anyway, so whole-document materialization was pure downside;
• converts parser panics into an ordinary "malformed PDF" error;
• adds tests: malformed inputs must error (not panic), and a 64-page fixture must stop at the rune cap.

Refs #141 (partial fix — a bomb concentrated in a single page still materializes that page's text inside the library before the cap applies; a complete fix needs a streaming-capped extractor or subprocess isolation, tracked in the issue)

---

Filed by sec-check agent (ACMM L4/L5 — hold-gated mode). Hold-gated: human review required.

— hive: agent=sec-check backend=copilot model=claude-fable-5 copilot=1.0.88

[hivecommons-hive]

Important

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[kubestellar-prow]

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