feat(kb): BS-7 - Zweitpruefer and supervisor for a Bachelor thesis at Bosch

User-confirmed 2026-09-11, extending the Arbeitszeugnis line about supervising
students and their theses.

Zweitpruefer (second examiner) is a FORMAL role carrying assessment
responsibility, not informal mentoring. That matters because "developing other
engineers" keeps appearing as a JD requirement and the profile has otherwise
only team-role evidence to offer - Security Champion, the Generali Java
community, Application Owner training. SBB asked for it explicitly and the
prepared answer had to fall back on exactly those.

Limits recorded with it: exactly ONE thesis is confirmed as second-examiner
work, so it must not be pluralised; the wider number of students supervised is
not recorded; and none of it is people management. `forbidden` now blocks
"supervised multiple theses", "lecturer", "taught a course" and an academic
appointment reading.

Carried into both data bundles so it can actually be selected - the BS-6 lesson
from the same week: evidence that reaches no bundle cannot be chosen.

Validator PASS, 37/37 tests.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qej5SBvhcbGXHwLqNWiskM

resume_builder/bundles/bundle_data_engineer.md

@@ -148,6 +148,10 @@ Same failure mode as BS-6 (Linux/Ansible), found the same week.
 - **Microsoft SQL Server (FC-1).** Fraunhofer's SCEDAS ran on MSSQL with C# and Entity Framework.
   Historical and single-project; do not present it as data-platform depth.
 - **Mentoring (BS-7).** *"Fachliche Betreuung von Studierenden, auch im Rahmen von
-  Abschlussarbeiten"* — documented technical supervision, including thesis supervision. Use it when
+  Abschlussarbeiten"* — documented technical supervision, including thesis supervision. He also
+  served as **Zweitprüfer (second examiner) and supervisor for one Bachelor thesis** at Bosch
+  (user-confirmed 2026-09-11) — a formal role carrying assessment responsibility, which is
+  materially stronger than the team-role evidence the profile otherwise falls back on. Use it when
   a JD asks about developing other engineers (SBB asked explicitly and the answer had to fall back
-  on team roles). **Technical supervision, NOT people management.**
+  on Security Champion and the Java community). **Technical supervision and formal examining, NOT
+  people management. Exactly one thesis as second examiner — do not pluralise.**