Address round-3 review on PR #914:
- When a glyph-corrupt doc's structured rung is NOT registered, the inline path
now falls through to OCR (with reason corrupt_glyphs), mirroring the external
next_available_tier instead of silently keeping the fast result. A structured
parse FAILURE remains terminal (tracked via structured_failed), matching the
external path which does not escalate a failure. Added a debug log for the
unregistered case and "(OCR not attempted)" to the failure warning.
- Tests: inline + external glyph-corrupt fallthrough to OCR when structured is
unregistered; glyph-corrupt + junk-quality both-flags precedence (structured
wins over the bad_text_layer/ocr route).
- Note the total_chars>0 mutual-exclusion with the scanned branch in
_route_from_signals.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
