fix: AI chat receives note body from open tabs instead of empty allContent

allContent is empty ({}) in Tauri mode because loadVaultData never
populates it — note content only enters allContent on explicit save.
mergeTabContent() enriches allContent with open tab content so the AI
context snapshot always includes the active note's body.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/utils/mergeTabContent.test.ts

@@ -0,0 +1,61 @@
+import { describe, it, expect } from 'vitest'
+import { mergeTabContent } from './mergeTabContent'
+
+describe('mergeTabContent', () => {
+  it('adds tab content when allContent is empty', () => {
+    const result = mergeTabContent({}, [
+      { entry: { path: '/vault/a.md' }, content: '# Hello\nBody text' },
+    ])
+    expect(result['/vault/a.md']).toBe('# Hello\nBody text')
+  })
+
+  it('overrides allContent with tab content (editor state is fresher)', () => {
+    const result = mergeTabContent(
+      { '/vault/a.md': 'old saved content' },
+      [{ entry: { path: '/vault/a.md' }, content: 'current editor content' }],
+    )
+    expect(result['/vault/a.md']).toBe('current editor content')
+  })
+
+  it('preserves allContent for paths without open tabs', () => {
+    const result = mergeTabContent(
+      { '/vault/b.md': 'other note content' },
+      [{ entry: { path: '/vault/a.md' }, content: '# Hello' }],
+    )
+    expect(result['/vault/b.md']).toBe('other note content')
+    expect(result['/vault/a.md']).toBe('# Hello')
+  })
+
+  it('returns original object when no tabs have content to merge', () => {
+    const original = { '/vault/a.md': 'content' }
+    expect(mergeTabContent(original, [])).toBe(original)
+  })
+
+  it('skips tabs with empty content', () => {
+    const original = { '/vault/a.md': 'content' }
+    const result = mergeTabContent(original, [
+      { entry: { path: '/vault/b.md' }, content: '' },
+    ])
+    expect(result).toBe(original)
+    expect(result['/vault/b.md']).toBeUndefined()
+  })
+
+  it('handles multiple tabs', () => {
+    const result = mergeTabContent({}, [
+      { entry: { path: '/vault/a.md' }, content: 'Note A' },
+      { entry: { path: '/vault/b.md' }, content: 'Note B' },
+    ])
+    expect(result['/vault/a.md']).toBe('Note A')
+    expect(result['/vault/b.md']).toBe('Note B')
+  })
+
+  it('does not mutate the original allContent object', () => {
+    const original = { '/vault/a.md': 'old' }
+    const result = mergeTabContent(original, [
+      { entry: { path: '/vault/a.md' }, content: 'new' },
+    ])
+    expect(original['/vault/a.md']).toBe('old')
+    expect(result['/vault/a.md']).toBe('new')
+    expect(result).not.toBe(original)
+  })
+})

src/utils/mergeTabContent.ts

@@ -0,0 +1,18 @@
+/**
+ * Merge open tab content into the allContent dictionary.
+ * Tab content takes priority (it reflects the current editor state).
+ * Returns the original object if no changes are needed (stable reference for useMemo).
+ */
+export function mergeTabContent(
+  allContent: Record<string, string>,
+  tabs: ReadonlyArray<{ entry: { path: string }; content: string }>,
+): Record<string, string> {
+  let merged: Record<string, string> | null = null
+  for (const tab of tabs) {
+    if (!tab.content) continue
+    if (allContent[tab.entry.path] === tab.content) continue
+    if (!merged) merged = { ...allContent }
+    merged[tab.entry.path] = tab.content
+  }
+  return merged ?? allContent
+}