feat(ai): add DB-backed church AI config provider

API/ROLAC.API/Services/Ai/ChurchAiConfig.cs

@@ -0,0 +1,13 @@
+namespace ROLAC.API.Services.Ai;
+
+/// <summary>Active AI configuration resolved from the ChurchProfile singleton (blanks filled with defaults).</summary>
+public sealed record ChurchAiConfig(
+    string Provider,
+    string ClaudeModel, string? ClaudeApiKey,
+    string GeminiModel, string? GeminiApiKey);
+
+/// <summary>Reads the church's AI settings from the database for the current request.</summary>
+public interface IChurchAiConfigProvider
+{
+    Task<ChurchAiConfig> GetAsync(CancellationToken ct = default);
+}

API/ROLAC.API/Services/Ai/ChurchAiConfigProvider.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore;
+using ROLAC.API.Data;
+
+namespace ROLAC.API.Services.Ai;
+
+/// <summary>
+/// Loads AI settings from the singleton <c>ChurchProfile</c> row, substituting default model names
+/// for any blank field so a freshly migrated install still names a valid model. The API keys are
+/// passed through as-is (null when unset → the calling service treats AI as disabled).
+/// </summary>
+public sealed class ChurchAiConfigProvider : IChurchAiConfigProvider
+{
+    private const string DefaultClaudeModel = "claude-haiku-4-5-20251001";
+    private const string DefaultGeminiModel = "gemini-2.5-flash-lite";
+
+    private readonly AppDbContext _db;
+    public ChurchAiConfigProvider(AppDbContext db) => _db = db;
+
+    public async Task<ChurchAiConfig> GetAsync(CancellationToken ct = default)
+    {
+        var p = await _db.ChurchProfiles.AsNoTracking().OrderBy(x => x.Id).FirstOrDefaultAsync(ct);
+
+        var provider = string.IsNullOrWhiteSpace(p?.AiProvider) ? "Claude" : p.AiProvider;
+        var claudeModel = string.IsNullOrWhiteSpace(p?.ClaudeModel) ? DefaultClaudeModel : p!.ClaudeModel!;
+        var geminiModel = string.IsNullOrWhiteSpace(p?.GeminiModel) ? DefaultGeminiModel : p!.GeminiModel!;
+
+        return new ChurchAiConfig(provider, claudeModel, p?.ClaudeApiKey, geminiModel, p?.GeminiApiKey);
+    }
+}