feat(application): commands/queries + IChargeableCharConfigService (PRC-001)

src/api/SIGCM2.Application/Pricing/ChargeableChars/IChargeableCharConfigService.cs

@@ -0,0 +1,21 @@
+namespace SIGCM2.Application.Pricing.ChargeableChars;
+
+/// <summary>
+/// PRC-001 — Application service for resolving active chargeable-char config for a Medio.
+///
+/// Priority rule: per-medio row overrides global (MedioId IS NULL) for the same Symbol.
+/// Returns a dictionary keyed by Symbol for O(1) lookup during word-count pricing.
+/// </summary>
+public interface IChargeableCharConfigService
+{
+    /// <summary>
+    /// Returns the resolved active config for the given medio as of the given date.
+    /// Per-medio rows take priority over global rows for the same Symbol.
+    /// Global rows are used as fallback when no per-medio row exists for that Symbol.
+    /// Returns an empty dictionary if no config exists at all.
+    /// </summary>
+    Task<IReadOnlyDictionary<string, ChargeableCharSnapshot>> GetActiveConfigForMedioAsync(
+        long medioId,
+        DateOnly asOf,
+        CancellationToken ct = default);
+}