v3.0.0-rc

🎉 Call Implemented!

v3.0.0-rc ships the LINE Calls implementation for linejs.

Highlights:

• PLANET outgoing 1:1 audio call signaling with setup, answer, keepalive, info response, and release handling.
• SRTP/Opus media send path for Android PLANET calls, including the native audio payload prefix.
• Opus encoder controls for frame duration, bitrate, bandwidth, and signal mode.
• Reusable example/call/call_on_command.ts sample: receive !call, place a call, and stream the bundled WAV.
• Updated call docs with a full flow writeup.
• Removed account-specific/debug call files from public examples.