fix(review-team): polish review settings localization

[limityan]

Localize AI error notifications

• Switch error presentation i18n keys from errors. to errors: namespace so notification copy renders from the shared errors locale bundle
• Replace formatDialogError with formatDialogErrorForNotification — returns structured object with severity, diagnostics, raw error, and actions
• handleDialogTurnFailed dispatches warning vs error based on presentation severity, adds "Copy diagnostics" action
• NotificationCenter renders expandable technical details panel for AI errors
• NotificationContextMenuProvider adds "Copy diagnostics" context menu item

Polish review settings localization

• Replace flat badge strip on Review Team page with clickable policy panel showing strategy, timeouts, split threshold, and max instances as metric tiles
• Add "Review workflow" overview section to Review settings page
• Normalize terminology across en-US/zh-CN/zh-TW locales (consistent "深度审查" usage, etc.)
• Tone down deep review badge styling — neutral text with purple icon accent