Build an iOS-first Sahara companion app after mobile workflow validation

[nidheesh-p]

Goal

Build an iOS-first Sahara companion app once the Shortcut-based workflow has been validated and the companion-app spike in #63 is complete.

Design: specs/CAPTURED_KNOWLEDGE_PLAN.md

Depends on #63.

Why

The current Shortcut path proves that mobile capture and recall are valuable, but it is still too manual for broad iPhone adoption. A lightweight app can make pairing, capture, recall, and Siri integration feel native.

Scope

• Build an iOS-first companion app that pairs to a desktop Sahara instance.
• Support QR-based device pairing and revocation.
• Store device secrets in iOS secure storage.
• Provide quick text capture and voice capture.
• Add a share extension for sending content from mobile apps into Sahara.
• Add lightweight recall over the private mobile API.
• Add an offline encrypted outbox with retry and idempotent replays.
• Add Siri App Intent support for capture and recall.
• Show capture status and recent sync outcomes.

Acceptance criteria

• Pairing works without manual token copying.
• A user can capture text or dictated memories in a few taps.
• A user can share text into Sahara from other iPhone apps.
• Offline captures retry safely without creating duplicates.
• Recall works without exposing the full desktop archive on the phone.
• The app does not run local embeddings or perform storage sync itself.

Out of scope

• Android implementation in this issue.
• Hosted multi-user sync or public webhook exposure.
• Full archive browsing, index management, or storage-configuration editing on mobile.