[app] Replace transition-all with explicit transition properties (6 spots)

Description

There are six transition-all usages in the app. transition-all makes the browser consider every animatable property on interaction, including unintended ones (box-shadow is paint; width is layout).

• packages/app/src/components/titlebar.tsx — opacity + translate
• packages/app/src/components/prompt-input/context-items.tsx — chip (box-shadow + background-color) and its remove button (color)
• packages/app/src/components/dialog-release-notes.tsx — pagination dots (width)
• packages/app/src/pages/session/timeline/message-timeline.tsx — scroll-to-bottom button (opacity + translate + scale)
• packages/app/src/pages/layout/sidebar-workspace.tsx — workspace icon (width + opacity)

Each is replaced with the exact properties that change. No visual or behavioral change; this is hygiene that also avoids accidental transitions when new classes are added later. Note: translate-*/scale-* use the translate/scale properties in this Tailwind version, and the transition lists account for that.

Plugins

none

OpenCode version

OpenCode Desktop 1.18.29

Steps to reproduce

1. Hover or interact with the affected elements
2. Inspect transition-property in DevTools: it reads all

Screenshot and/or share link

No screenshot — no visual difference.

Operating System

CachyOS (Arch Linux), KDE Plasma 6.7.5, Wayland

Terminal

n/a (desktop app)