Multi message storage

[HarukiToreda]

Overview

This PR introduces multi-message storage and threaded conversation view support to BaseUI, improving how messages are displayed, stored, and preserved across sessions.

Features

• Message Storage

  • Stores the last 20 messages in RAM.
  • Persists the last 20 messages to flash on properly initiated reboot/shutdown
    (not hard power cut or reset button press).
  • Automatically restores saved messages from flash into RAM on boot.
  • Added debug logs showing the exact space used when saving to flash and the
    space restored on boot.

• Conversation Threads

  • Messages are displayed newest to oldest with timestamps in an auto-scrollable thread view.
  • Sent messages are labeled as “Me”.
  • Incoming messages are automatically sorted into the correct thread (DM or Channel broadcast).
  • Auto-focuses on the last active conversation when a new message arrives.
  • Uses boot time counter if no RTC is available, and once valid time is obtained,
    messages are updated and written with the corrected timestamp for persistence.
  • Conversation Menu Options:
    • Switch between conversation views (Channels, DMs, or All).
    • Reply directly to the currently focused conversation.
    • Dismiss Last: remove the oldest message in the current conversation.
    • Dismiss All: clear all messages (when in View All).

• Message Status Indicators (for sent messages)

  • ✅ Checkmark = confirmed ACK.
  • ❌ X = failed or timed-out.
  • ⚠️ Exclamation mark = relayed but no ACK.

• Client Integration

  • Messages created on other clients (phone/web) are captured and added into the correct thread.

Additional Changes

• Removed legacy message handling from Screen.cpp.
• Cleaned up CannedMessageModule by removing legacy message sending and temporary message logic.
• Fixed Emote screen rendering issues.
• Added autofocus to message screen after sending a new message.
• Favorite Node screens jump to conversation with action menu option.

[HarukiToreda]

big change, we switched from dynamic std::string storage to fixed-size char[] to reduce flash build size