The pptx payload hides where an audience watching the slides does not look. The
extractor surfaces all three regions into the concept text so the stage-2 scan
catches the injection:
- speaker notes (slide.notes_slide.notes_text_frame.text);
- off-slide (off-canvas) text boxes (shape.text_frame.text, position-agnostic);
- image/shape alt-text (cNvPr@descr, read off the XML — python-pptx 1.0.2 has no
stable public accessor across shape types).
Detach-proof: same visible slide without notes ADMITs. python-pptx imported
lazily (dev/showcase-scoped, not a core dep). Tests 305 -> 310.
Kjell Tore Guttormsen
d8a95e465f