feat(app): real Driven app icon + tray (road-to-cloud, C2)

Replace the placeholder gold-square icon with the chosen C2 concept:
a flat two-color (white-on-deep-teal) road-to-cloud glyph. Hand-author
a clean square full-bleed SVG master (icon.svg) - white multi-bump
cloud at top, white road tapering up into it with a dashed teal
centerline - plus a simplified monochrome template tray glyph
(tray.svg: cloud + up chevron, solid black on transparent for
trayIcon iconAsTemplate). Render the master to 1024px with resvg and
regenerate the full Tauri icon set (32/128/128@2x png, icon.ico,
icon.icns, Windows Store logos) via cargo tauri icon. Verified
cargo build -p driven-app is green (valid .ico/.icns resource embed).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CyiRqk2DVwmJjEu5gcD1m

Author: pmaxhogan