feat(v3): migrate workspace to API, Tauri desktop, and v3 crates; remove legacy MCP stack

- Add apps/api, desktop Tauri shell, domain/application/crypto/device-auth/infrastructure-db
- Replace desktop-daemon vault integration; drop secrets-core and secrets-mcp*
- Ignore apps/desktop/dist and generated Tauri icons; document icon/dist steps in AGENTS.md
- Apply rustfmt; fix clippy (collapsible_if, HTTP method as str)

crates/desktop-daemon/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "secrets-desktop-daemon"
+version = "0.1.0"
+edition.workspace = true
+
+[lib]
+name = "secrets_desktop_daemon"
+path = "src/lib.rs"
+
+[[bin]]
+name = "secrets-desktop-daemon"
+path = "src/main.rs"
+
+[dependencies]
+anyhow.workspace = true
+axum.workspace = true
+dotenvy.workspace = true
+reqwest = { workspace = true, features = ["stream"] }
+rmcp.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+tokio.workspace = true
+tracing.workspace = true
+tracing-subscriber.workspace = true
+
+secrets-device-auth = { path = "../device-auth" }