add config-driven channel label and dev-workstation bootstrap

A bleeding-edge container running next to a stable one on the same dev box is easy to confuse, and a branch-only badge would force perpetual rebase/cherry-pick drift between main and dev-be. Instead the badge is config-driven: the settings endpoint injects a synthetic env_label from SHOPDB_ENV_LABEL, the sidebar renders a red DEV tag only when it is non-empty, and stable simply leaves it unset. Same code on both channels, no divergence.

dev-bootstrap.ps1 makes a fresh Windows box turnkey: it checks git/Docker (winget-installs with a prompt), verifies the engine is actually running, then builds and starts an isolated per-channel stack so stable and edge coexist on distinct ports, projects, and volumes. docker-compose.channel.yml is a thin overlay so the base compose file stays channel-agnostic.

shopdb/core/api/settings.py

@@ -64,6 +64,40 @@ PUBLIC_SETTING_KEYS = {
     'site_timezone',
 }
 
+# Environment channel label. Sourced from the SHOPDB_ENV_LABEL environment
+# variable (set by the edge docker-compose override and the bleeding-edge
+# installer, unset on stable/main), NOT from a settings row. It is injected as a
+# synthetic public item into the settings list so the frontend picks it up
+# through the same read-through it already uses for branding, with no extra
+# request. Empty when unset, which is how a stable deployment renders no DEV
+# badge. Public and read-only: it carries no secret and cannot be edited via the
+# settings API, only by redeploying with a different environment value.
+ENV_LABEL_KEY = 'env_label'
+
+
+def _env_label() -> str:
+    """The configured environment channel label (e.g. 'DEV'), or '' when unset."""
+    return (os.environ.get('SHOPDB_ENV_LABEL') or '').strip()
+
+
+def _env_label_item() -> dict:
+    """Synthetic, serialized settings item carrying the environment label.
+
+    Shaped like a real serialized Setting so the frontend read-through treats it
+    as just another public key. settingid is None because it is not a DB row.
+    """
+    return {
+        'settingid': None,
+        'key': ENV_LABEL_KEY,
+        'value': _env_label(),
+        'valuetype': 'string',
+        'category': 'branding',
+        'description': 'Environment channel label (from SHOPDB_ENV_LABEL); '
+                       'drives the DEV badge in the sidebar. Read-only.',
+        'createddate': None,
+        'modifieddate': None,
+    }
+
 
 def _plugin_declared_settings() -> dict:
     """Declared settings ({key: entry}) of every loaded plugin, or {}."""
@@ -576,7 +610,19 @@ def list_settings():
     # bootstrap keys); an authed principal sees everything (secrets masked).
     if get_jwt_identity() is None:
         settings = [s for s in settings if _is_public_setting(s)]
-    return success_response([_serialize_setting(s) for s in settings])
+    items = [_serialize_setting(s) for s in settings]
+
+    # Inject the environment channel label as a synthetic public item so the
+    # frontend read-through surfaces it alongside branding. It is env-sourced,
+    # not a DB row, and is always present (empty string when unset) so the
+    # public-settings contract can rely on the key existing. Drop any DB row that
+    # somehow shares the key so the env value is authoritative and appears once.
+    # Skip it when a category filter is active and does not select branding, so a
+    # scoped query is not polluted.
+    if not category or category == 'branding':
+        items = [i for i in items if i.get('key') != ENV_LABEL_KEY]
+        items.append(_env_label_item())
+    return success_response(items)
 
 
 @settings_bp.route('/<key>', methods=['GET'])