feat(startup): wire startup repo path from CLI to UI

The app now supports opening a repository at startup by
reading a --repo argument and passing the path to the UI.
A new startup repository state is managed in the backend and
exposed via a tauri command and event, enabling the frontend
to auto-open the repository when ready. The UI adds a small
startup flow with retry handling to ensure the path is
consumed once available.
- Reads --repo or --repo=PATH and resolves relative paths
- Signals UI to open startup repo via open-startup-repository
- Frontend retries opening the repo until it succeeds

src/App.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { onDestroy, onMount, tick } from "svelte";
   import { getVersion } from "@tauri-apps/api/app";
+  import { listen } from "@tauri-apps/api/event";
   import { getCurrentWindow } from "@tauri-apps/api/window";
   import { open as openDialog } from "@tauri-apps/plugin-dialog";
   import { check, type DownloadEvent, type Update } from "@tauri-apps/plugin-updater";
@@ -275,6 +276,10 @@
   // ── State ──────────────────────────────────────────────────────────────────
 
   let repoPath = "";
+  let startupReady = false;
+  let pendingStartupRepoPath = "";
+  let startupRepositoryRetryTimer: ReturnType<typeof setTimeout> | undefined;
+  let unlistenStartupRepository: (() => void) | undefined;
   let activeRepoPath = "";
   let activeView: AppView = "management";
   let repoTabs: RepoTab[] = [];
@@ -543,6 +548,14 @@
     themeMediaQuery = window.matchMedia("(prefers-color-scheme: light)");
     themeMediaQuery.addEventListener("change", handleSystemThemeChange);
     void runStartupSequence();
+    void listen("open-startup-repository", () => {
+      void receiveStartupRepository();
+    }).then((unlisten) => {
+      if (appShuttingDown) unlisten();
+      else unlistenStartupRepository = unlisten;
+    }).catch(() => {
+      // Browser preview has no Tauri event system.
+    });
     void refreshDetectedExternalTools();
     void getVersion().then((version) => { appVersion = version; }).catch(() => { appVersion = ""; });
     window.addEventListener("beforeunload", handleAppShutdown);
@@ -565,7 +578,9 @@
     window.removeEventListener("beforeunload", handleAppShutdown);
     window.removeEventListener("pagehide", handleAppShutdown);
     unlistenCloseRequested?.();
+    unlistenStartupRepository?.();
     if (cloneDialogErrorTimer) clearTimeout(cloneDialogErrorTimer);
+    if (startupRepositoryRetryTimer) clearTimeout(startupRepositoryRetryTimer);
     Object.values(errorAutoHideStates).forEach((state) => {
       if (state?.timer) clearTimeout(state.timer);
     });
@@ -642,6 +657,8 @@
       if (remainingSplashTime > 0) await wait(remainingSplashTime);
 
       await closeStartupSplashscreen();
+      startupReady = true;
+      await receiveStartupRepository();
       startBackgroundTimers();
       // Remote access can take seconds (offline networks, SSH negotiation,
       // credential helpers). It must never hold the startup screen hostage.
@@ -650,6 +667,29 @@
     }
   }
 
+  async function receiveStartupRepository() {
+    try {
+      const path = await tracedInvoke<string | null>("take_startup_repository");
+      if (path) pendingStartupRepoPath = path;
+    } catch {
+      return;
+    }
+
+    if (!startupReady || !pendingStartupRepoPath) return;
+    if (isBusy) {
+      if (!startupRepositoryRetryTimer) {
+        startupRepositoryRetryTimer = setTimeout(() => {
+          startupRepositoryRetryTimer = undefined;
+          void receiveStartupRepository();
+        }, 100);
+      }
+      return;
+    }
+    const path = pendingStartupRepoPath;
+    pendingStartupRepoPath = "";
+    await openRepo(path);
+  }
+
   async function fetchOpenRepositoriesDuringStartup() {
     const paths = uniqueRepoPaths(repoTabs.map((tab) => tab.path));
     if (paths.length === 0 || backgroundFetchInFlight) return;