Admin write-CRUD, Home Assistant connector config, wiring audit

Three requested phases.

1) Admin section (SDD §8.7) — MudBlazor inline-dialog CRUD, consistent pattern,
   delete guards, snackbar feedback, shared Confirm helper:
   - Energy types: create/edit/delete (blocks delete when meters reference it).
   - Meters: create/edit/delete; recomputes consumption when mode/baseline
     changes (NormalizationService over a fresh factory context, in a tx);
     delete cascades data (consumption+readings are Restrict → removed first).
   - A meter's ingest sources: manage on the meter-detail Sources tab
     (add/edit/delete MQTT/Tasmota/HA sources with typed config).
   - Tariffs: full CRUD (scope/component/value/validity).
   - Cost categories: CRUD + member management (meter or energy-type members).
   - Connectors: ingestion_endpoint CRUD (MQTT broker + Home Assistant);
     secrets referenced by env-var name only, never stored.
   - Settings: read-only effective-config view (settings are env-driven and
     reproducible, so an editable form would change nothing — kept honest).
   PV role is now editable on meters (MeterMeta.SetRole can clear a role).

2) Read Home Assistant — extracted a shared public HaEndpointConfig (was a
   private record in the worker), added HaConnectionTester (powers the connector
   "Test connection": checks base URL + env-resolved token, optionally reads one
   entity). Configuring an HA connector + an HA source on a meter drives the
   existing REST-poll worker end to end. (WebSocket push stays a future
   optimization; REST poll already reads HA.)

3) Wiring/placeholder audit — swept every OnClick/Href: all handlers are real,
   all internal links resolve to real routes, no TODO/stub/placeholder code.
   Fixed one genuine gap: MainLayout had no drawer toggle, so the nav was
   unreachable on narrow screens — added a hamburger button.

Tests: +6 (MeterMeta.SetRole role-removal; HaConnectionTester fail-closed
guard branches with a throwing HttpClientFactory proving no network on bad
config); render test now covers all admin routes. 69 Core + 45 Integration =
114 green. Live-verified in Docker: all admin pages 200, drawer toggle present,
Settings shows real effective config.

Claude-Session: https://claude.ai/code/session_01Lz2RqAsnQhetqWNoCDfexK

src/Infrastructure/Ingestion/HaEndpointConfig.cs

@@ -0,0 +1,47 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace MeterVault.Infrastructure.Ingestion;
+
+/// <summary>
+/// The parsed <see cref="Core.Domain.IngestionEndpoint.Config"/> JSON for a Home Assistant
+/// connection (SDD §6.2). The long-lived token is stored by reference only: <see cref="TokenEnv"/>
+/// names an environment variable resolved at runtime — never the token itself (SDD §6.4).
+/// </summary>
+public sealed record HaEndpointConfig
+{
+    private static readonly JsonSerializerOptions Options = new()
+    {
+        PropertyNameCaseInsensitive = true,
+        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+    };
+
+    /// <summary>Base URL of the Home Assistant instance, e.g. <c>http://homeassistant.local:8123</c>.</summary>
+    public string? BaseUrl { get; init; }
+
+    /// <summary>Name of the environment variable holding the long-lived access token.</summary>
+    public string? TokenEnv { get; init; }
+
+    public static HaEndpointConfig Parse(string? json)
+    {
+        if (string.IsNullOrWhiteSpace(json))
+        {
+            return new HaEndpointConfig();
+        }
+
+        try
+        {
+            return JsonSerializer.Deserialize<HaEndpointConfig>(json, Options) ?? new HaEndpointConfig();
+        }
+        catch (JsonException)
+        {
+            return new HaEndpointConfig();
+        }
+    }
+
+    public string ToJson() => JsonSerializer.Serialize(this, Options);
+
+    /// <summary>Resolves the token from the referenced environment variable (null if unset).</summary>
+    public string? ResolveToken() =>
+        string.IsNullOrWhiteSpace(TokenEnv) ? null : Environment.GetEnvironmentVariable(TokenEnv);
+}