Prepare CodexBar Plasma 0.2.36 with the reviewed changes since 0.2.35. Align metadata and the dated changelog, leave Unreleased empty, and refresh the release-related screenshot descriptions.

Validation: make check passed with 894 QtTests and 62 Python tests, without skips. make package and tagged changelog extraction passed. Verified package contents, metadata, translations, README links, and SHA-256 checksum.