Polish app for design review

[cbusillo]

Summary

• Remove the remaining decorative status glyph/dial treatment from the app shell.
• Replace the header and detail gauges with text-first capacity summaries and bars.
• Widen the default app window to avoid clipping the three-pane review layout.
• Clean up the app widget-preview section indentation/copy so it is ready for a design pass.

Validation

• scripts/commit-gate.sh passed with 62 tests.
• xcodegen generate --spec project.yml succeeded.
• xcodebuild -project ContextPanel.xcodeproj -scheme ContextPanel -configuration Debug -destination 'platform=macOS' -allowProvisioningUpdates build succeeded.
• Launched the native Debug app and captured a visual sanity screenshot at /tmp/context-panel-design-polish-2.png.

Design handoff

• Local gitignored handoff created at handoff-to-codex-design.md for the upcoming Codex Design review.