Add SpineEventEngine repository submodules to summit manifest

[Copilot]

This PR wires summit to track the requested SpineEventEngine repositories as Git submodules. It adds the full submodule manifest and corresponding gitlink entries at repo root.

• Submodule manifest (.gitmodules)

  • Added entries for:
    • base-libraries, core-jvm, validation, tool-base, config, compiler, time, logging, jdbc-storage, core-jvm-compiler, ProtoTap, base-types, testlib, change, reflect, money
  • All URLs point to https://github.com/SpineEventEngine/<name>.git.

• Root submodule links

  • Added root-level submodule paths matching the same list so each repo is tracked as a submodule in this repository.

• Example manifest entry

  [submodule "core-jvm"]
  	path = core-jvm
  	url = https://github.com/SpineEventEngine/core-jvm.git

Original prompt

Please add the following repositories as Git submodules:

• base-libraries
• core-jvm
• validation
• tool-base
• delivery-server
• config
• compiler
• time
• logging
• jdbc-storage
• core-jvm-compiler
• ProtoTap
• base-types
• testlib
• change
• reflect
• money

[alexander-yevsyukov]

LGTM