Launcher Polish - Phase 10: Settings Panel Polish

[Emperiusm]

Task

Implement Phase 10 — Settings Panel Polish from the launcher UI polish plan.

Plan Reference

docs/superpowers/plans/2026-04-03-launcher-ui-polish.md

Read the plan's Phase 10 section. Phases 0–9 are already merged. All primitives (icons, bold text, dropdowns, layout helpers) are available.

Tasks (16)

Task	Summary
TASK-066	Settings sub-nav (sidebar or tab-based section navigation)
TASK-067	Settings section headers with icons
TASK-068	Breadcrumb header for Settings
TASK-069	Dropdown width constraints
TASK-070	Display settings — 2-column dropdown grid with icons
TASK-071	Toggle card surfaces for boolean settings
TASK-072	Slider control for numeric settings
TASK-073	Audio section — input/output dropdowns with ICON_SPEAKER/ICON_MIC
TASK-074	Audio test buttons
TASK-075	Keyboard shortcut display
TASK-076	Security section layout
TASK-077	About/version info section
TASK-078	Sidebar footer — user avatar circle
TASK-079	Avatar initials rendering
TASK-080	Settings save/apply flow
TASK-081	Settings reset to defaults

Constraints

• After each task, run cargo check -p prism-client.
• After all tasks, run cargo test --workspace.
• Update the Progress Tracker: check off Phase 10 and Pass 4.
• Single commit: feat(client): Phase 10 — settings panel polish
• Branch: launcher-polish/phase-10
• Do NOT modify files outside crates/prism-client/.

Labels

launcher-polish, phase-10, pass-4