Add background-hash-mark addition for region routing

Per https://buymeacoffee.com/ripplebiz/region-filtering:

> After some discussions, and that there is some confusion
around #channels and #regions, it's been decided to drop
the requirement to have the '#' prefix. So, region names
will just be plain alphanumeric (and '-'), with no # prefix.

> For backwards compatibility, the names will internally have
a '#' prepended, but for all client GUI's and command lines,
you generally won't see mention of '#' prefixes. The next
firmware release (v1.12.0) and subsequent Ripple firmware
and Liam's app will have modified UI to remove the '#' requirement.

So, silently add, but don't duplicate, for users who have already
added hashmarks.

app/radio.py

@@ -262,10 +262,11 @@ class RadioManager:
 
                     # Apply flood scope from settings (best-effort; older firmware
                     # may not support set_flood_scope)
+                    from app.region_scope import normalize_region_scope
                     from app.repository import AppSettingsRepository
 
                     app_settings = await AppSettingsRepository.get()
-                    scope = app_settings.flood_scope
+                    scope = normalize_region_scope(app_settings.flood_scope)
                     try:
                         await mc.commands.set_flood_scope(scope if scope else "")
                         logger.info("Applied flood_scope=%r", scope or "(disabled)")

app/region_scope.py

@@ -0,0 +1,20 @@
+"""Helpers for normalizing MeshCore flood-scope / region names."""
+
+
+def normalize_region_scope(scope: str | None) -> str:
+    """Normalize a user-facing region scope into MeshCore's internal form.
+
+    Region names are now user-facing plain strings like ``Esperance``.
+    Internally, MeshCore still expects hashtag-style names like ``#Esperance``.
+
+    Backward compatibility:
+    - blank/None stays disabled (`""`)
+    - existing leading ``#`` is preserved
+    """
+
+    stripped = (scope or "").strip()
+    if not stripped:
+        return ""
+    if stripped.startswith("#"):
+        return stripped
+    return f"#{stripped}"

app/routers/channels.py

@@ -9,6 +9,7 @@ from app.dependencies import require_connected
 from app.models import Channel, ChannelDetail, ChannelMessageCounts, ChannelTopSender
 from app.radio import radio_manager
 from app.radio_sync import upsert_channel_from_radio_slot
+from app.region_scope import normalize_region_scope
 from app.repository import ChannelRepository, MessageRepository
 from app.websocket import broadcast_event
 
@@ -153,7 +154,7 @@ async def set_channel_flood_scope_override(
     if not channel:
         raise HTTPException(status_code=404, detail="Channel not found")
 
-    override = request.flood_scope_override.strip() or None
+    override = normalize_region_scope(request.flood_scope_override) or None
     updated = await ChannelRepository.update_flood_scope_override(channel.key, override)
     if not updated:
         raise HTTPException(status_code=500, detail="Failed to update flood-scope override")

app/routers/messages.py

@@ -14,6 +14,7 @@ from app.models import (
     SendDirectMessageRequest,
 )
 from app.radio import radio_manager
+from app.region_scope import normalize_region_scope
 from app.repository import AmbiguousPublicKeyPrefixError, AppSettingsRepository, MessageRepository
 from app.websocket import broadcast_error, broadcast_event
 
@@ -31,12 +32,12 @@ async def _send_channel_message_with_effective_scope(
     action_label: str,
 ) -> Any:
     """Send a channel message, temporarily overriding flood scope when configured."""
-    override_scope = (channel.flood_scope_override or "").strip()
+    override_scope = normalize_region_scope(channel.flood_scope_override)
     baseline_scope = ""
 
     if override_scope:
         settings = await AppSettingsRepository.get()
-        baseline_scope = settings.flood_scope
+        baseline_scope = normalize_region_scope(settings.flood_scope)
 
     if override_scope and override_scope != baseline_scope:
         logger.info(

app/routers/settings.py

@@ -6,6 +6,7 @@ from fastapi import APIRouter
 from pydantic import BaseModel, Field
 
 from app.models import AppSettings
+from app.region_scope import normalize_region_scope
 from app.repository import AppSettingsRepository
 
 logger = logging.getLogger(__name__)
@@ -123,8 +124,7 @@ async def update_settings(update: AppSettingsUpdate) -> AppSettings:
     # Flood scope
     flood_scope_changed = False
     if update.flood_scope is not None:
-        stripped = update.flood_scope.strip()
-        kwargs["flood_scope"] = stripped
+        kwargs["flood_scope"] = normalize_region_scope(update.flood_scope)
         flood_scope_changed = True
 
     if kwargs: