build(amd-h): vendor GlobalPlatform exports for j3r452 builds

Drops gpapi-globalplatform 1.7 and gpapi-upgrade 1.1 (AMD-H Amendment H
v1.1) under applet/build-tools/gp-amdh/, sourced from
OpenJavaCard/globalplatform-exports (master snapshot 2020-09-30).

- dt-mvn.sh mounts exports/org/ into the converter's api_export_files/.
- pom.xml adds the .jar files as system-scope deps under the j3r452
  profile so javac on j3r452 builds resolves org.globalplatform.upgrade
  symbols (j3r180 builds don't see them on classpath).
- .gitignore: narrow build-tools/ exclusion to top-level only so the new
  applet/build-tools/gp-amdh/ tree is trackable while the top-level
  build-tools/jcardsim/ vendor fork stays out of the repo.

This commit alone produces zero CAP bytecode change because no current
source imports org.globalplatform.*. The infra is provably inert until
the Task 3.1+ source on feat/amd-h-epic-3-wip is merged. Verified by
diffing CAP zip components for both profiles: only the embedded
Java-Card-CAP-Creation-Time timestamp in META-INF/MANIFEST.MF differs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -1,6 +1,9 @@
 # --- pre-existing ---
-# Local build/test tooling, not committed (jcardsim fork etc.)
-build-tools/
+# Local build/test tooling, not committed (jcardsim fork etc.). Matches the
+# top-level build-tools/ dir only — applet/build-tools/ is a different beast
+# (vendored AMD-H exports etc.) and IS committed; see negation below.
+/build-tools/
+!applet/build-tools/
 
 # --- secrets / private keys ---
 # aliro-trustgen emits aliro_trust.h with the reader's PRIVATE scalar.