Scaffold workspace, shared types and requirements spec

Cargo workspace with core/ble/fit/probe crates. crates/core/src/types.rs
is the fixed contract between the BLE layer, ride engine and UI.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src-tauri/Cargo.toml

@@ -0,0 +1,40 @@
+[package]
+name = "bikecontrol-app"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+description = "BikeControl desktop shell: Tauri commands and the event bridge to the UI"
+
+[lib]
+# Tauri v2 convention: the app lives in a lib so the same code can be reused by
+# the Android/iOS entry points later (G-4).
+name = "bikecontrol_app_lib"
+crate-type = ["staticlib", "cdylib", "rlib"]
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+bikecontrol-core = { workspace = true }
+
+tauri = { version = "2", features = [] }
+tauri-plugin-dialog = "2"
+
+serde = { workspace = true }
+serde_json = { workspace = true }
+serde_yaml_ng = { workspace = true }
+tokio = { workspace = true }
+anyhow = { workspace = true }
+thiserror = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
+
+[features]
+default = ["mock-ride"]
+# Drive the UI from the synthetic ride simulator in `src/mock.rs`. This is what
+# ships today, while `crates/core` and `crates/ble` are still being written.
+mock-ride = []
+# Drive the UI from `bikecontrol_core::RideSession` fed by real FTMS telemetry.
+# Swap `default` to this once core's `session`/`physics` are implemented.
+real-session = []