v0.3.0

Bugfix release.

What's in v0.3.0

Restores Wi-Fi connectivity after a failed first association attempt.
NVS is now written when the user commits the password (not after
GOT_IP), so the typed credentials survive any number of failed
attempts and any number of reboots. The X (forget) key on the
network-info screen remains the single, explicit way to remove them.

Flash modes

The web flasher picks the right binary for you:

• App update only — preserves your saved settings and Wi-Fi
  credentials. Use this to upgrade an already-configured device.
• Full flash — wipes everything (keyer settings + Wi-Fi
  credentials). Use this on a new device or to recover from a
  misconfiguration.

For manual flashing with esptool.py, the canonical filenames are
listed below.