license: restore derivation/attribution clause to LICENSE condition 2

Makes the modifications-must-indicate-derivation + author-name-intact
requirement explicit in the operative LICENSE (it was only implied by
condition 2's attribution language), matching the README. Consistent
with Dual-Use v1.1 intent; no terms loosened.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: jgravelle

LICENSE

@@ -47,7 +47,10 @@ CONDITIONS (all uses)
    than the original author as the author of this software, and you
    may not represent the original author as the author, publisher,
    maintainer, sponsor, or endorser of any modified, renamed, or
-   redistributed version.
+   redistributed version. Any modifications made to the software must
+   clearly indicate that they are derived from the original work, and
+   the name of the original author (J. Gravelle) must remain intact.
+   He's kinda full of himself.
 
 3. The software may not be used, directly or indirectly, in any
    product, service, or workflow that generates revenue, is offered