fix(frontend): CodebaseAnalytics dashboard has rendering gaps and hidden content #4063

While fixing data validation issues, discovered that CodebaseAnalytics dashboard has layout/rendering problems causing some sections to not display data properly.

User Report

• 'Some divs does not show codebase analytics test results'
• 'Some content is hidden'
• 'Empty divs with no content in different places'
• 'Loading spinner stuck indefinitely'
• 'Error messages showing in some sections'

Fixes Applied (Related)

• bug(deps): protobuf version incompatibility with chromadb opentelemetry dependencies #3971: CodeQualityDashboard data validation (complexity, healthScore, metrics, patterns)
• This prevents crashes but doesn't fully solve content visibility issues

Issues Remaining

1. Some sections not loading data completely
2. Layout may be hiding content (overflow, z-index issues)
3. CSS constraints possibly clipping content
4. Some sections stuck on loading state
5. Error messages not all visible to user

Affected Components

• CodebaseAnalytics.vue (main orchestration)
• CodeQualityDashboard.vue (partially fixed)
• CodebaseChartsSection.vue
• CodebaseDependenciesPanel.vue
• Other analytics sub-panels

Investigation Needed

1. Full end-to-end data flow for each panel
2. CSS overflow/height constraints review
3. Loading state management
4. Error handling visibility
5. Z-index stacking issues

Related

• bug(deps): protobuf version incompatibility with chromadb opentelemetry dependencies #3971: CodeQualityDashboard data validation (partial fix)
• Session: debugging with user to identify root causes