feat: show blocking modal when vault has no git repo, offer auto-init

When opening a vault without a .git directory, a blocking modal prevents
app use until the user either creates a repository (git init + add +
commit) or chooses another vault. The check runs via is_git_repo Tauri
command; browser mode fails open.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src-tauri/src/commands/git.rs

@@ -128,6 +128,20 @@ pub async fn git_remote_status(vault_path: String) -> Result<GitRemoteStatus, St
         .map_err(|e| format!("Task panicked: {e}"))?
 }
 
+#[cfg(desktop)]
+#[tauri::command]
+pub fn is_git_repo(vault_path: String) -> bool {
+    let vault_path = expand_tilde(&vault_path);
+    std::path::Path::new(vault_path.as_ref()).join(".git").is_dir()
+}
+
+#[cfg(desktop)]
+#[tauri::command]
+pub fn init_git_repo(vault_path: String) -> Result<(), String> {
+    let vault_path = expand_tilde(&vault_path);
+    crate::git::init_repo(&vault_path)
+}
+
 // ── Git commands (mobile stubs) ─────────────────────────────────────────────
 
 #[cfg(mobile)]
@@ -230,3 +244,15 @@ pub async fn git_remote_status(_vault_path: String) -> Result<GitRemoteStatus, S
         behind: 0,
     })
 }
+
+#[cfg(mobile)]
+#[tauri::command]
+pub fn is_git_repo(_vault_path: String) -> bool {
+    false
+}
+
+#[cfg(mobile)]
+#[tauri::command]
+pub fn init_git_repo(_vault_path: String) -> Result<(), String> {
+    Err("Git init is not available on mobile".into())
+}

src-tauri/src/lib.rs

@@ -138,6 +138,8 @@ pub fn run() {
             commands::get_conflict_mode,
             commands::git_resolve_conflict,
             commands::git_commit_conflict_resolution,
+            commands::is_git_repo,
+            commands::init_git_repo,
             commands::check_claude_cli,
             commands::stream_claude_chat,
             commands::stream_claude_agent,

src/App.tsx

@@ -50,12 +50,14 @@ import { UpdateBanner } from './components/UpdateBanner'
 import { FlatVaultMigrationBanner } from './components/FlatVaultMigrationBanner'
 import { useFlatVaultMigration } from './hooks/useFlatVaultMigration'
 import { invoke } from '@tauri-apps/api/core'
+import { invoke } from '@tauri-apps/api/core'
 import { isTauri, mockInvoke } from './mock-tauri'
 import type { SidebarSelection, InboxPeriod } from './types'
 import type { NoteListItem } from './utils/ai-context'
 import { filterEntries, filterInboxEntries, type NoteListFilter } from './utils/noteListHelpers'
 import { openNoteInNewWindow } from './utils/openNoteWindow'
 import { isNoteWindow, getNoteWindowParams } from './utils/windowMode'
+import { GitRequiredModal } from './components/GitRequiredModal'
 import './App.css'
 
 // Type declarations for mock content storage and test overrides
@@ -95,6 +97,24 @@ function App() {
 
   // When onboarding resolves to a different vault path, update the switcher
   const resolvedPath = noteWindowParams?.vaultPath ?? (onboarding.state.status === 'ready' ? onboarding.state.vaultPath : vaultSwitcher.vaultPath)
+  // Git repo check: 'checking' | 'required' | 'ready'
+  const [gitRepoState, setGitRepoState] = useState<'checking' | 'required' | 'ready'>('checking')
+  useEffect(() => {
+    if (!resolvedPath) return
+    setGitRepoState('checking')
+    const check = isTauri()
+      ? invoke<boolean>('is_git_repo', { vaultPath: resolvedPath })
+      : Promise.resolve(true) // browser mock: assume git
+    check
+      .then(isGit => setGitRepoState(isGit ? 'ready' : 'required'))
+      .catch(() => setGitRepoState('ready')) // fail open
+  }, [resolvedPath])
+
+  const handleInitGitRepo = useCallback(async () => {
+    if (isTauri()) await invoke('init_git_repo', { vaultPath: resolvedPath })
+    setGitRepoState('ready')
+  }, [resolvedPath])
+
   const vault = useVaultLoader(resolvedPath)
   useVaultConfig(resolvedPath)
   const { settings, loaded: settingsLoaded, saveSettings } = useSettings()
@@ -392,6 +412,23 @@ function App() {
     return <LoadingView />
   }
 
+  // Show git-required modal when vault has no git repo (skip for note windows)
+  if (!noteWindowParams && gitRepoState === 'required') {
+    return (
+      <div className="app-shell">
+        <GitRequiredModal
+          onCreateRepo={handleInitGitRepo}
+          onChooseVault={vaultSwitcher.handleOpenLocalFolder}
+        />
+      </div>
+    )
+  }
+
+  // Show loading spinner while checking git status
+  if (!noteWindowParams && gitRepoState === 'checking' && onboarding.state.status === 'ready') {
+    return <LoadingView />
+  }
+
   // Show telemetry consent dialog on first launch (skip for note windows)
   if (!noteWindowParams && settingsLoaded && settings.telemetry_consent === null) {
     return (

src/components/GitRequiredModal.test.tsx

@@ -0,0 +1,51 @@
+import { render, screen, fireEvent, waitFor } from '@testing-library/react'
+import { describe, it, expect, vi } from 'vitest'
+import { GitRequiredModal } from './GitRequiredModal'
+
+describe('GitRequiredModal', () => {
+  it('renders title and explanation', () => {
+    render(<GitRequiredModal onCreateRepo={vi.fn()} onChooseVault={vi.fn()} />)
+    expect(screen.getByText('Git repository required')).toBeInTheDocument()
+    expect(screen.getByText(/track changes/)).toBeInTheDocument()
+  })
+
+  it('renders both action buttons', () => {
+    render(<GitRequiredModal onCreateRepo={vi.fn()} onChooseVault={vi.fn()} />)
+    expect(screen.getByText('Create repository')).toBeInTheDocument()
+    expect(screen.getByText('Choose another vault')).toBeInTheDocument()
+  })
+
+  it('calls onCreateRepo when primary button clicked', async () => {
+    const onCreateRepo = vi.fn().mockResolvedValue(undefined)
+    render(<GitRequiredModal onCreateRepo={onCreateRepo} onChooseVault={vi.fn()} />)
+    fireEvent.click(screen.getByText('Create repository'))
+    expect(onCreateRepo).toHaveBeenCalledOnce()
+  })
+
+  it('calls onChooseVault when secondary button clicked', () => {
+    const onChooseVault = vi.fn()
+    render(<GitRequiredModal onCreateRepo={vi.fn()} onChooseVault={onChooseVault} />)
+    fireEvent.click(screen.getByText('Choose another vault'))
+    expect(onChooseVault).toHaveBeenCalledOnce()
+  })
+
+  it('disables buttons and shows spinner while creating', async () => {
+    let resolve: () => void
+    const onCreateRepo = vi.fn().mockReturnValue(new Promise<void>(r => { resolve = r }))
+    render(<GitRequiredModal onCreateRepo={onCreateRepo} onChooseVault={vi.fn()} />)
+    fireEvent.click(screen.getByText('Create repository'))
+    await waitFor(() => {
+      expect(screen.getByText('Creating…')).toBeInTheDocument()
+    })
+    resolve!()
+  })
+
+  it('shows error message when creation fails', async () => {
+    const onCreateRepo = vi.fn().mockRejectedValue(new Error('Permission denied'))
+    render(<GitRequiredModal onCreateRepo={onCreateRepo} onChooseVault={vi.fn()} />)
+    fireEvent.click(screen.getByText('Create repository'))
+    await waitFor(() => {
+      expect(screen.getByText(/Permission denied/)).toBeInTheDocument()
+    })
+  })
+})

src/components/GitRequiredModal.tsx

@@ -0,0 +1,57 @@
+import { useState } from 'react'
+import { GitBranch } from '@phosphor-icons/react'
+
+interface GitRequiredModalProps {
+  onCreateRepo: () => Promise<void>
+  onChooseVault: () => void
+}
+
+export function GitRequiredModal({ onCreateRepo, onChooseVault }: GitRequiredModalProps) {
+  const [creating, setCreating] = useState(false)
+  const [error, setError] = useState<string | null>(null)
+
+  const handleCreate = async () => {
+    setCreating(true)
+    setError(null)
+    try {
+      await onCreateRepo()
+    } catch (err) {
+      setError(err instanceof Error ? err.message : String(err))
+      setCreating(false)
+    }
+  }
+
+  return (
+    <div className="flex h-full w-full items-center justify-center" style={{ background: 'var(--sidebar)' }}>
+      <div className="flex max-w-sm flex-col items-center gap-5 rounded-xl border border-border bg-background p-8 shadow-lg">
+        <GitBranch size={36} className="text-muted-foreground" />
+        <h2 className="m-0 text-lg font-semibold text-foreground">Git repository required</h2>
+        <p className="m-0 text-center text-[13px] leading-relaxed text-muted-foreground">
+          Laputa uses a git repository to track changes, detect moved files, and keep your vault safe.
+          We'll create a local repo — no remote needed.
+        </p>
+        {error && (
+          <p className="m-0 rounded-md bg-destructive/10 px-3 py-2 text-center text-[12px] text-destructive">
+            {error}
+          </p>
+        )}
+        <div className="flex w-full flex-col gap-2">
+          <button
+            className="w-full cursor-pointer rounded-md bg-primary px-4 py-2 text-[13px] font-medium text-primary-foreground transition-colors hover:bg-primary/90 disabled:cursor-not-allowed disabled:opacity-50"
+            onClick={handleCreate}
+            disabled={creating}
+          >
+            {creating ? 'Creating…' : 'Create repository'}
+          </button>
+          <button
+            className="w-full cursor-pointer rounded-md border border-border bg-transparent px-4 py-2 text-[13px] font-medium text-foreground transition-colors hover:bg-muted disabled:cursor-not-allowed disabled:opacity-50"
+            onClick={onChooseVault}
+            disabled={creating}
+          >
+            Choose another vault
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}