[swegener-rtp]

Summary

Updated the API mockup to use the official GEISA Schemas 0.9.0 releasein the specification repo.

Details

• pointed the schemas submodule at geisa/specification
• pinned it to the exact schemas-v0.9.0 release commit
• updated waveform discovery/stream handling for the 0.9.0 API
• updated instantaneous quantities for the 0.9.0 field model
• updated the test client for the renamed 0.9.0 fields
• updated documentation for the preserved schemas tag

NOTE: The previous schema pin was a pre-release state 42 commits before the actual Schemas 0.9.0 release.

Validation:

• Linux (ubuntu 22.04.xx LTS ARM) make clean all passed
• all binaries linked successfully
• make lint passed
• clang-format passed
• clang-tidy completed with (many, but pre-existing) warnings only
• git diff --check passed