Browser control moved from CEF to native WebKit

Kaji's browser surface was migrated away from the embedded CEF/Puppeteer stack to a native WebKit-based view. The app keeps the in-app browser workflow, but drops a large amount of Chromium runtime packaging complexity.

• Migrated browser panes and controller actions to native WebKit infrastructure
• Removed CEF bridge sources and CEF runtime install validation scripts
• Updated browser screenshot, read-page, dialog, navigation, and device-profile paths
• Kept browser automation anchored to Kaji-owned browser sessions
• Updated browser architecture documentation

Browser MCP became a packaged tool surface

The browser MCP infrastructure was refactored into a broader tool catalog with a packaged install path. Browser actions are now described through dedicated command, action, target, and resource locator layers.

• Added KajiBrowserControlBroker, command registry, action aliases, and target arguments
• Added capture, diagnostic, file, interaction, and navigation action modules
• Added KajiBrowserMCPResourceLocator and KajiBrowserMCPInstallService
• Updated coding-agent browser environment wiring
• Added tests for browser MCP installation

Release packaging got smaller and safer

The release scripts were updated for the WebKit migration, and the shipped app rpath was fixed so packaged framework loading behaves correctly in the release artifact.

• Removed CEF runtime installation from the release path
• Updated build-release.sh and smoke-release-app.sh
• Added SwiftRunBundleLauncher updates for packaged app launching
• Fixed the release app framework rpath
• Bumped Kaji to 0.3.1