Cleanup: remove dead CSS from CodebaseAnalytics.vue after component extraction (#1579)

[mrveiss]

Problem

After the decomposition in PR #2236 (#1579), CodebaseAnalytics.vue still has 1,073 lines of <style scoped> CSS. Many selectors now reference elements that were extracted into child components:

Dead selectors (template moved to child components)

• .summary-card severity variants (.critical, .high, .medium, .low, .info, .type-*) — moved to ProblemsReportSection.vue and CodebaseChartsSection.vue
• .code-intelligence-section, .code-intel-tabs — moved to CodebaseSecurityPanel.vue
• .card-header-content, .refresh-indicator — moved to CodebaseOverviewPanel.vue
• .enhanced-analytics-grid, .metrics-grid, .metric-item — moved to dashboard panels
• .communication-metrics, .performance-details, .quality-details — moved to dashboard panels
• .btn-debug, .btn-cancel — moved to AnalyticsHeaderControls.vue
• .source-selector-row, .source-select, .btn-manage-sources — moved to SourceManager.vue

Impact

Since Vue's <style scoped> only applies to elements in the component's own template, these selectors have zero effect. They add ~500+ lines of dead weight.

Suggested approach

1. Audit each CSS selector against the current template (lines 1-339)
2. Remove selectors whose target elements are no longer in the parent template
3. Move any needed styles to the respective child components if not already present there
4. Verify no visual regressions after cleanup

Discovered During

Implementing #1579 (PR #2236)

Impact

Low — dead code, no functional effect, but adds maintenance burden and makes the file harder to navigate.

[github-actions]

PR #2249 (merged to Dev_new_gui) references this issue with a close keyword.

cleanup(analytics): remove 826 lines of dead CSS from CodebaseAnalytics.vue (#2244)

If this issue is fully resolved, close it manually. If work remains, no action is needed.

[mrveiss]

Closed via PR #2249 merge to Dev_new_gui.