[WIP] Map Rebirth .rbs data to Hyphon internal models

[Copilot]

• Extend AutomationLane.parameter union to cover all RBS automation params (resonance, decay, envAmount for both 303s and PCF)
• Add slideTime optional field to Bass2Params and SynthParams in types.ts
• Add slideTime optional field to Tb303PatternA/Tb303PatternB in importer types.ts
• Update RbsImporter to: encode accent via timbre, handle new automation params, map slideTime
• Update Open303Manager.applyBass2Params() to apply slideTime when present
• Fix handleRbsImport in useSongStorage to wire songArrangement data (trackStorage + songStructure)
• Add/extend tests for new behavior