fix(bootstrap): stabilize sidebar toggle

[ViaxCo]

Fixes sidebar toggle behaviour across desktop and mobile.

• Prevents mobile content-pane click handling from double-processing sidebar toolbar clicks
• Adds fallback handling when a sidebar toggle animation leaves the mode unchanged
• Keeps desktop/mobile sidebar mode detection from fighting responsive layouts
• Avoids suppressing the app’s own toolbar toggle bridge command
• Adds regression coverage for desktop, mobile, hidden controls, bridge echoes, and delayed toggle messages