fix(copyright): recover narrative author attributions

[mstykow]

Summary

• recover contactless passive, first-person, and provenance-style author credits when the candidate has person-name structure
• join bounded wrapped first-person credits and remove incomplete initial-only prefixes once the full name is known
• preserve explicit narrative credits through the scanner source-code guard without weakening arbitrary source-code rejection

Issues

• Covers: False-positives when comparing provenant with scancode-toolkit output #1391

Scope and exclusions

• Included: rewritten by, as authored by me, Name, and artifact provenance such as documentation is taken from ... by Name
• Explicit exclusions: tool names, generated artifacts, generic teams, numeric product identities, and arbitrary contactless by prose

How to verify

• Scan Perl 5.38.4 with --copyright: exactly three author records are added over the parent—Nicholas Clark, Ozan S. Yigit, and Marc Lehmann—with no copyright or holder changes.
• Repeat on InfoZIP 3.0, musl, Dancer2, and Valgrind 3.25.1: author, copyright, and holder results are identical to the parent.
• Full common-profile compare artifacts: .provenant/compare-runs/20260903T040653Z-perl-5.38.4-58241 and .provenant/compare-runs/20260903T040825Z-zip30-58597.

Intentional differences from Python

• Provenant keeps the explicit Ozan S. Yigit credit that ScanCode misses and reports Marc Lehmann from the direct documentation provenance statement, while rejecting ScanCode author noise such as product names and prose fragments.
• Provenant keeps GPL references in InfoZIP change history as clues rather than treating removed GPL code as an applicable file license.

Follow-up work

• Created or intentionally deferred: the common-profile InfoZIP review exposed one valid abbreviated-name credit (Chr. Spieler) still missing; that is isolated to the next stacked layer.

Expected-output fixture changes

• Files changed: none
• Why the new expected output is correct: focused detector and scanner contracts cover the new behavior without changing checked-in golden output.

[mstykow]

@greptileai review