maarcadetweet: initial commit

AT Protocol PDS + AppView + Tauri Desktop Client, 160-char post limit.

- PDS (Rust + axum + sqlx)
  - Auth: createAccount, createSession, refreshSession
  - Records: createRecord, deleteRecord (race-safe via SELECT FOR UPDATE)
  - Feed: feed.like.create, feed.repost.create
  - Sync: getRepo, getBlocks, getLatestCommit, getRecord (with MST proof), listRepos
  - Identity: resolveHandle
  - MST: spec-conformant (at-mst crate, 27 tests)
  - Repo: signed commits, TID counter (monotonic, 4096 wrap safe)

- AppView (Rust + axum + sqlx)
  - Jetstream consumer (WebSocket, exponential backoff, 38k+ events indexed)
  - REST API: timeline/home (graph-aware), profile, search, post (with thread hydration)
  - Handle-sync worker (did:plc + did:web)
  - JSONB embed storage + thread columns (migration 0003)
  - Like/repost counter cache (migration 0004)

- Tauri 2 + Svelte 5 Desktop Client
  - System tray (Show/Compose/Quit menu)
  - OS notifications (tauri-plugin-notification)
  - Auto-update (tauri-plugin-updater, placeholder endpoint)
  - Window-state (tauri-plugin-window-state)
  - 160-char compose with live counter
  - Image/Link embed rendering
  - LocalStorage-persisted like state
  - Timeline with poll (prepend new posts)
  - Custom TitleBar (transparent, no decorations)
  - Orange/IBM Plex Mono maarcade design

Tests: 231 Rust + 9 vitest = 240 passed.

crates/tauri-app/vite.config.ts

@@ -0,0 +1,32 @@
+import { defineConfig } from "vite";
+import { svelte } from "@sveltejs/vite-plugin-svelte";
+import { viteStaticCopy } from "vite-plugin-static-copy";
+
+const host = process.env.TAURI_DEV_HOST;
+
+export default defineConfig(async () => ({
+  plugins: [
+    svelte(),
+    viteStaticCopy({
+      targets: [
+        { src: "src/assets/fonts/*", dest: "fonts" },
+      ],
+    }),
+  ],
+  clearScreen: false,
+  server: {
+    port: 1430,
+    strictPort: true,
+    host: host || false,
+    hmr: host
+      ? { protocol: "ws", host, port: 1431 }
+      : undefined,
+    watch: { ignored: ["**/src-tauri/**"] },
+  },
+  envPrefix: ["VITE_", "TAURI_ENV_*"],
+  build: {
+    target: process.env.TAURI_ENV_PLATFORM === "windows" ? "chrome105" : "safari13",
+    minify: !process.env.TAURI_ENV_DEBUG ? "esbuild" : false,
+    sourcemap: !!process.env.TAURI_ENV_DEBUG,
+  },
+}));