fix(app): show project logos throughout settings

[opencode-agent]

Summary

• add a shared app-level ProjectIcon component that derives project display name, image source, and color from one project object
• reuse it in Settings → Projects, the edit-project navigation, and the editable icon preview
• preserve uploaded icons, generated logos, color-only avatars, unsaved icon edits, and existing fallback behavior

Checks

• bun test --conditions=solid --only-failures --preload ./happydom.ts ./src/shell/layout/helpers.test.ts (17 passing)
• bun x prettier --check src/settings/workspaces/projects.tsx src/settings/workspaces/project-dialog.tsx src/shell/layout/project-icon.tsx
• focused TSX transpilation and shared-project-icon assertions for all changed components
• full app typecheck currently reports unrelated existing workspace/dependency errors

Requested by: @Brendonovich (Brendan via Slack)