feat: save mobile note frontmatter

apps/mobile/src/mobileDemoVault.ts

@@ -1,6 +1,8 @@
 import { demoNoteSources } from './demoData'
 import type { MobileEditorDraft } from './mobileEditorDraft'
 import { saveMobileEditorDraft } from './mobileEditorDraftSave'
+import { saveMobileNoteFrontmatter } from './mobileNoteFrontmatterSave'
+import type { WritableMobileNoteFrontmatter } from './mobileNoteFrontmatterWrite'
 import { createMobileNoteFile } from './mobileNoteCreate'
 import {
   createMobileVaultConfigFromMetadata,
@@ -51,6 +53,23 @@ export async function deleteDemoVaultNote(noteId: string, vaultMetadata = defaul
   }).deleteNote(noteId)
 }
 
+export function saveDemoVaultNoteFrontmatter({
+  metadata,
+  noteId,
+  vaultMetadata = defaultMobileVaultMetadata,
+}: {
+  metadata: WritableMobileNoteFrontmatter
+  noteId: string
+  vaultMetadata?: MobileVaultMetadata
+}) {
+  return saveMobileNoteFrontmatter({
+    metadata,
+    noteId,
+    storage: createNativeMobileVaultStorage(),
+    vault: createDemoVaultConfig(vaultMetadata),
+  })
+}
+
 function demoVaultFiles(): MobileVaultFile[] {
   return demoNoteSources.map((source) => ({
     path: source.filename,

apps/mobile/src/mobileNoteFrontmatterSave.test.ts

@@ -0,0 +1,65 @@
+import { describe, expect, it } from 'vitest'
+import { saveMobileNoteFrontmatter } from './mobileNoteFrontmatterSave'
+import { createMobileVaultConfig } from './mobileVaultConfig'
+import { createMemoryMobileVaultStorage } from './mobileVaultStorage'
+
+const vault = createVault()
+
+describe('mobile note frontmatter save', () => {
+  it('updates note frontmatter through vault storage', async () => {
+    const storage = createMemoryMobileVaultStorage([
+      {
+        path: 'notes/workflow.md',
+        content: '---\ntitle: Workflow\nprivate: true\n---\n# Workflow',
+      },
+    ])
+
+    await expect(saveMobileNoteFrontmatter({
+      metadata: {
+        status: 'Draft',
+        tags: ['mobile'],
+        type: 'Project',
+      },
+      noteId: 'notes/workflow',
+      storage,
+      vault,
+    })).resolves.toEqual({
+      status: 'saved',
+      path: 'notes/workflow.md',
+    })
+
+    await expect(storage.readMarkdownFile(vault, 'notes/workflow.md')).resolves.toBe([
+      '---',
+      'title: Workflow',
+      'private: true',
+      'type: Project',
+      'status: Draft',
+      'tags: [mobile]',
+      '---',
+      '# Workflow',
+    ].join('\n'))
+  })
+
+  it('returns missing when the note file does not exist', async () => {
+    const storage = createMemoryMobileVaultStorage([])
+
+    await expect(saveMobileNoteFrontmatter({
+      metadata: { type: 'Essay' },
+      noteId: 'missing',
+      storage,
+      vault,
+    })).resolves.toEqual({
+      status: 'missing',
+      path: 'missing.md',
+    })
+  })
+})
+
+function createVault() {
+  const result = createMobileVaultConfig({ id: 'personal', name: 'Personal Journal' })
+  if (!result.ok) {
+    throw new Error(result.error)
+  }
+
+  return result.config
+}

apps/mobile/src/mobileNoteFrontmatterSave.ts

@@ -0,0 +1,41 @@
+import type { MobileVaultConfig } from './mobileVaultConfig'
+import type { MobileVaultStorageDriver } from './mobileVaultStorage'
+import {
+  writeMobileNoteFrontmatter,
+  type WritableMobileNoteFrontmatter,
+} from './mobileNoteFrontmatterWrite'
+
+export type MobileNoteFrontmatterSaveResult =
+  | {
+      status: 'saved'
+      path: string
+    }
+  | {
+      status: 'missing'
+      path: string
+    }
+
+export async function saveMobileNoteFrontmatter({
+  metadata,
+  noteId,
+  storage,
+  vault,
+}: {
+  metadata: WritableMobileNoteFrontmatter
+  noteId: string
+  storage: MobileVaultStorageDriver
+  vault: MobileVaultConfig
+}): Promise<MobileNoteFrontmatterSaveResult> {
+  const path = notePath(noteId)
+  const content = await storage.readMarkdownFile(vault, path)
+  if (content === null) {
+    return { status: 'missing', path }
+  }
+
+  await storage.writeMarkdownFile(vault, path, writeMobileNoteFrontmatter({ content, metadata }))
+  return { status: 'saved', path }
+}
+
+function notePath(noteId: string) {
+  return `${noteId}.md`
+}

docs/MOBILE_PROGRESS.md

@@ -77,12 +77,13 @@ This file is the resumable working log for Tolaria mobile. The strategy and road
 - Deferred archive as a first-class mobile note state until the mobile vault schema/frontmatter model is explicit; implementing archive now as file movement would create throwaway semantics that may conflict with desktop-compatible metadata.
 - Added mobile frontmatter metadata parsing for stored markdown notes, including type, icon, date, and inline tags, so app-local vault scans can project note metadata instead of hardcoding every stored note as a generic file.
 - Added mobile frontmatter serialization helpers that can create/update supported type/status/date/icon/tags fields while preserving unknown metadata lines.
+- Added a mobile frontmatter save boundary that updates persisted note metadata through the vault storage driver and exposes the same path through the demo vault facade for future properties UI calls.
 
 ## Next Action
 
 Continue Phase 4 with editor durability:
 
-1. Wire mobile property edits to the frontmatter read/write helpers for type/date/status/icon/tags.
+1. Wire the mobile properties panel to the frontmatter save boundary for type/date/status/icon/tags.
 2. Expand TenTap Markdown serialization coverage for common writing constructs and preserve unsupported blocks without corrupting files.
 3. Add simulator interaction coverage for create/open/edit/autosave/delete using a development-client path or another route that avoids Expo Go's overlay controls.
 
@@ -271,6 +272,11 @@ Continue Phase 4 with editor durability:
 - CodeScene after mobile frontmatter serialization helpers: `apps/mobile/src/mobileNoteFrontmatterWrite.ts` and `apps/mobile/src/mobileNoteFrontmatterWrite.test.ts` scored `10`.
 - `pnpm --filter @tolaria/mobile test` passed after mobile frontmatter serialization helpers: 24 files / 78 tests.
 - `pnpm --filter @tolaria/mobile exec expo export --platform ios --output-dir /tmp/tolaria-mobile-export` passed after mobile frontmatter serialization helpers.
+- `pnpm --filter @tolaria/mobile test -- src/mobileNoteFrontmatterSave.test.ts src/mobileNoteFrontmatterWrite.test.ts` passed after mobile frontmatter save boundary: 25 files / 80 tests.
+- `pnpm --filter @tolaria/mobile typecheck` passed after mobile frontmatter save boundary.
+- CodeScene after mobile frontmatter save boundary: `apps/mobile/src/mobileNoteFrontmatterSave.ts`, `apps/mobile/src/mobileNoteFrontmatterSave.test.ts`, and `apps/mobile/src/mobileDemoVault.ts` scored `10`.
+- `pnpm --filter @tolaria/mobile test` passed after mobile frontmatter save boundary: 25 files / 80 tests.
+- `pnpm --filter @tolaria/mobile exec expo export --platform ios --output-dir /tmp/tolaria-mobile-export` passed after mobile frontmatter save boundary.
 
 ## Risks / Watch Items