feat: Round 19 — Privacy-first multi-platform social hub (Instagram/Messenger/Facebook/X)

[wallydz-bot]

Round 19 — Operation Multiplatform

Overview

Transforms messenger-desktop from a single Messenger wrapper into a privacy-first all-in-one social hub supporting 4 platforms.

Platforms Added

• 📸 Instagram — instagram.com/direct/inbox/
• 💬 Messenger — messenger.com (existing)
• 👥 Facebook — facebook.com/messages/
• 𝕏 X (Twitter) — x.com/messages

New Files

• src-tauri/src/platform_manager.rs — Platform enum, URL mapping, navigate command, last-platform persistence
• src-tauri/src/privacy_engine.rs — Session isolation, cookie clearing on quit, CSP per platform, telemetry blocking
• src/platform-selector.ts — Platform selection TypeScript
• src/index.html — Beautiful dark privacy-first platform selector UI

Modified Files

• src-tauri/src/lib.rs — Wired PlatformManager + PrivacyEngine, on_quit cookie clear
• src-tauri/tauri.conf.json — Multi-platform CSP, local platform selector as initial URL
• src/injection/index.ts — Platform-aware injection guard

Privacy Features

• Session isolation: each platform stores data in app_data_dir/sessions/<platform>/
• Zero persistence: all cookies/localStorage cleared on app quit
• Telemetry blocking: CSP blocks doubleclick.net, google-analytics.com, analytics.facebook.com
• Platform-specific CSP: tight CSP per platform, only allows required CDNs

Quality

• cargo check: 0 errors, 0 warnings
• cargo test: 63/63 pass (includes new unit tests for PlatformManager + PrivacyEngine)
• 6 commits across 5 waves (kimi → coder → mistral → devstral → willy)