Bam 0.12.0 — onboarding, Prism & Clear, palette, profiles, extensions

Merges two parallel draft lines into one release (build 26).

Onboarding and Space appearances

• Full-screen first-run onboarding: burst-icon welcome, Space color pick with live retinting, first-Space naming and symbol, optional Chrome bookmark-bar favorite import, interactive ⌘T/⌘S training, a user-initiated default-browser offer and a confetti finale. Keyboard-first, skippable, minimizable, Reduce Motion aware. Replay via Bam ▸ Welcome to Bam…; existing profiles are never re-welcomed.
• Two new Space appearances: Prism, a slowly shifting spectrum, and Clear, a translucent window over a behind-window blur that lets the desktop show through. Pick them in Manage Spaces or onboarding; they apply only by explicit choice.

Command palette, profiles and extensions

• Redesigned translucent command palette with Arc-style rows and Tab-to-search for nineteen sites, with URL-shaped text kept out of remote autocomplete.
• Named login profiles per Space (shared or separate website data) and a local-folder WebKit extension host on macOS 15.4+ (no store installs or native messaging yet).

All fourteen component suites and nine native suites passed on the tagged tree; see VALIDATION.md for scope and limits. Development prerelease, Apple Silicon, locally signed — not notarized.