feat(tabs): add inline tab actions

[helbertm]

Summary

• add per-tab close actions revealed on hover/focus and persistently available for coarse touch input
• move tab rename actions into each tab while preserving keyboard shortcuts and focus restoration
• turn the existing header X into a guarded Close all action with exact tab-count confirmation
• keep the New tab action immediately after the last open tab
• simplify inline action chrome so hover/focus treatments do not compete with the tab border

Accessibility and UX

• keep action controls outside role="tablist" while visually aligning them with their tabs
• preserve localized accessible names in en-US, pt-BR, and es-ES
• restore focus to the resulting active tab after close
• put initial destructive-dialog focus on Cancel
• cover desktop and coarse-touch behavior with zero axe violations

Validation

• npm run validate:full:ci
• npm run validate:dependencies (0 vulnerabilities)
• npm run quality:docker
• npm run quality:security:docker (npm audit and OSV: no issues)
• npm run validate:browser:quality
• npm run validate:native:chromium

Release Please should derive the next release as 0.6.0 after this PR reaches master.