v2.1.0 — Dioxus 0.7 stable

Retargeted to Dioxus 0.7 stable. 2.0 depended on the 0.8.0-alpha.0 pre-release, which Cargo won't unify with 0.7.x — making the crate unusable in projects on shipped 0.7. The code needed no changes; only the dependency requirement moved.

Verified against 0.7.9: library (all features), the wasm32 web build, every gallery example, and 109 tests (76 lib + 33 runtime) plus doc-tests compile and pass with zero warnings.

The crate still declares dioxus with default-features = false, features = ["minimal"], so it pulls in no renderer of its own. Stores, which back the in-app drag state, have been part of Dioxus since 0.7.0.

Full diff: #11