chore: bump version to 2.0.2

Workspace version 2.0.1 -> 2.0.2 (Cargo.toml + lock, workspace crates only —
no dependency re-resolution), a new metainfo <release> entry, and the release
docs: TAG_DETAILS.md (human-facing, About-modal/website format, 2.0.2 section
prepended above 2.0.1/2.0.0) + CHANGELOG.md (full detail since v2.0.1 — the
headless daemon, kiosk mode, dynamic background, cast/quality #638, audio,
rendering #617, library, themes and security work). Codename inherited on the
patch line; About-modal literal untouched.

cc

crates/Cargo.toml

@@ -42,7 +42,7 @@ members = [
 ]
 
 [workspace.package]
-version = "2.0.1"
+version = "2.0.2"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/vicrodh/qbz"