chore(desktop): update dev environment icons and add docs

Update development icons for desktop app in various sizes and formats.
Add Claude configuration directory and UI redesign specification docs.

Author: praxstack

docs/09-temp/ui-redesign-spec.md

@@ -0,0 +1,37 @@
+# UI Redesign Spec
+
+## Reference Design
+See HTML mockup provided by user. Key elements:
+
+### Sidebar
+- "New Session" button with icon, primary color border
+- "RECENT CHATS" section header (uppercase, tracking-wider)
+- Chat items with icon + title + timestamp
+- "CONTEXT" section with file list
+- Bottom: plan usage bar
+
+### Message Timeline
+- Assistant: Robot icon (32x32 rounded square) + "OPENCODE AI" label (uppercase, primary color, bold)
+- User: Timestamp + "You" label (accent-cyan color, bold)
+- User message: Glass panel, rounded-2xl with rounded-tr-none
+
+### Thinking Block
+- Collapsible `<details>` with:
+  - Cyan pulsing dot + "Thinking process..." text
+  - Expand/collapse arrow
+  - Mono font content with `>` prefix
+  - Border-top separator
+
+### Prompt Input
+- Glass panel with backdrop-blur
+- Model selector pills ("GPT-4o", "Web Search")
+- Textarea
+- Send button with primary color + glow shadow
+- Bottom bar: keyboard shortcuts + sync status
+
+### Right Activity Bar
+- Vertical icon strip: Extensions, Source Control, History
+- Bottom: Settings + user avatar
+
+### Settings (from screenshot)
+- Already looks reasonable, minor polish needed