v2.0.0 — Complete rebuild. Everything is now free, forever.

• Removed all Pro/Free gating — 600% volume boost, visualizer, and all features unlocked for everyone
• Replaced Lemon Squeezy licensing with a Ko-fi support link
• New: Mono Toggle — merge stereo channels into one (perfect for one-earbud use)
• New: Channel Pan slider — balance audio left or right
• New: EQ Profiles — "Clear Voice" (+8dB at 2.5kHz for speech clarity) and "Bass Engine" (+10dB low-shelf for bass boost)
• New: Night Shift preset — low-pass filter + warm compression + subtle pitch shift for late-night listening
• New: 6 scene presets (Movie, Music, Podcast, Night Shift, Clear Voice, Bass Engine) + saveable My Mix
• Rebuilt audio pipeline: GainNode → Compressor → Low-Pass → EQ Peak → EQ Shelf → StereoPanner → Mono Mix → Analyser
• Upgraded visualizer with cyan/violet gradient bars and VIZ_BOOST_PRO amplification
• Full UI redesign: Professional Audio Rack aesthetic, dark mode, neon cyan/violet accents
• Manifest downgraded to MV2 for full Firefox Web Audio API compatibility