Core ride logic, FTMS client, FIT encoder and probe CLI

Adds backing state for Resistance and Erg control modes, which had no
value to hold and so could never satisfy FR-4.3/FR-4.6.

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

ui/vite.config.ts

@@ -0,0 +1,22 @@
+import { defineConfig } from 'vite';
+import { svelte } from '@sveltejs/vite-plugin-svelte';
+
+// Tauri drives this dev server; the port is fixed and must match
+// src-tauri/tauri.conf.json's devUrl.
+export default defineConfig({
+  plugins: [svelte()],
+  clearScreen: false,
+  server: {
+    port: 1420,
+    strictPort: true,
+    watch: {
+      // Rust sources are rebuilt by cargo, not by vite.
+      ignored: ['**/src-tauri/**'],
+    },
+  },
+  build: {
+    target: 'esnext',
+    sourcemap: false,
+    chunkSizeWarningLimit: 1200,
+  },
+});