Encore: 2 Bundled Encore Features and Settings UI Updates

[needmorecowbell]

Summary

• Implements a full extension system ("Encore Features") for Maestro with manifest-based discovery, sandboxed activation, scoped storage, and an IPC bridge for main↔renderer communication
• Ships two bundled first-party encores: Agent Status Exporter (real-time agent data to JSON) and Notification Webhook (HTTP notifications on agent events)
• Extracts Director's Notes settings into its own EncoreFeatureCard, creating a flat, uniform feature list in Settings → Encore tab
• All encores are off by default, lazy-loaded on toggle, and persist enabled/disabled state across restarts

What's included

Core system (src/main/encore-*.ts, src/shared/encore-types.ts):

• Manifest format with permissions model (process:read, storage, settings:*, notifications, network)
• Loader with bundled-encore bootstrapping from dist/encores/ → userData/encores/
• Host with scoped API surface per encore (storage, IPC, settings, process read, notifications)
• Storage with path traversal prevention (rejects .., absolute paths, null bytes, separators)
• IPC bridge for encore:<id>:<channel> message routing

UI (src/renderer/components/):

• EncoreFeatureCard — shared toggle card wrapper used by both Director's Notes and Plugins
• DirectorNotesSettings — extracted ~380 LOC from SettingsModal into self-contained component
• EncoreManager — browse/enable/disable encores with per-encore settings panels
• EncoreTabContent — sandboxed iframe renderer for encores with UI
• Keyboard shortcut: Ctrl+Shift+X opens Encore tab (when plugins feature enabled)

State persistence fix:

• Replaced broken userDisabled flag with symmetric encore:<id>:enabled boolean
• enableEncore() → sets true, disableEncore() → sets false, startup restores only explicit true
• No auto-enable for first-party encores

Test plan

• npm run lint passes
• All 480 test files pass (20,332 tests)
• New test coverage: encore-activation, encore-host, encore-loader, encore-reference, EncoreManager, EncoreTabContent, useEncoreRegistry
• Manual: Settings → Encore tab shows flat list with Director's Notes and Plugins as peer cards
• Manual: Toggle encore on → persists across npm run dev restarts; toggle off → stays off
• Manual: Agent Status Exporter writes JSON when enabled with output path configured
• Manual: Notification Webhook fires HTTP POST on agent completion/error

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features

  • Added Encore Features system for installable plugins, with UI for browsing, enabling/disabling, and per-plugin settings.
  • Bundled Agent Status Exporter and Notification Webhook plugins.
  • Right panel support for plugin tabs and a keyboard shortcut (Meta+Shift+X) to open Encore features.

• Documentation

  • Comprehensive developer and user guides for the Encore system and plugin manifests.