feat: add SpamShield router for spam detection and call analysis

- Create tRPC router with checkNumber, classifySMS, classifyCall endpoints
- Add protected procedures for rule CRUD, feedback submission, and stats
- Implement service layer with phone number normalization and audit logging
- Add ML engine with BERT stub, feature extraction, and rule engine
- Implement reputation API module with circuit breaker and caching
- Write comprehensive tests (34 tests) for all layers
- Wire spamshield router into app root router

web/src/server/api/routers/spamshield.ts

@@ -0,0 +1,75 @@
+import { wrap } from "@typeschema/valibot";
+import { createTRPCRouter, publicProcedure, protectedProcedure } from "../utils";
+import {
+  CheckNumberSchema,
+  ClassifySMSSchema,
+  ClassifyCallSchema,
+  CreateRuleSchema,
+  DeleteRuleSchema,
+  FeedbackSchema,
+  StatsFilterSchema,
+} from "../schemas/spamshield";
+import * as spamshieldService from "~/server/services/spamshield.service";
+
+export const spamshieldRouter = createTRPCRouter({
+  checkNumber: publicProcedure
+    .input(wrap(CheckNumberSchema))
+    .query(async ({ input }) => {
+      return spamshieldService.checkNumberReputation(input.phoneNumber);
+    }),
+
+  classifySMS: publicProcedure
+    .input(wrap(ClassifySMSSchema))
+    .query(async ({ input }) => {
+      return spamshieldService.classifySMS(input.text);
+    }),
+
+  classifyCall: publicProcedure
+    .input(wrap(ClassifyCallSchema))
+    .query(async ({ input }) => {
+      return spamshieldService.classifyCall(
+        input.callerNumber,
+        input.duration,
+        input.timeOfDay,
+      );
+    }),
+
+  getRules: protectedProcedure.query(async ({ ctx }) => {
+    return spamshieldService.getRules(ctx.user.id);
+  }),
+
+  createRule: protectedProcedure
+    .input(wrap(CreateRuleSchema))
+    .mutation(async ({ ctx, input }) => {
+      return spamshieldService.createRule(
+        ctx.user.id,
+        input.ruleType,
+        input.pattern,
+        input.action,
+        input.priority,
+      );
+    }),
+
+  deleteRule: protectedProcedure
+    .input(wrap(DeleteRuleSchema))
+    .mutation(async ({ ctx, input }) => {
+      return spamshieldService.deleteRule(ctx.user.id, input.ruleId);
+    }),
+
+  submitFeedback: protectedProcedure
+    .input(wrap(FeedbackSchema))
+    .mutation(async ({ ctx, input }) => {
+      return spamshieldService.submitFeedback(
+        ctx.user.id,
+        input.phoneNumber,
+        input.isSpam,
+        input.feedbackType,
+      );
+    }),
+
+  getStats: protectedProcedure
+    .input(wrap(StatsFilterSchema))
+    .query(async ({ ctx, input }) => {
+      return spamshieldService.getStats(ctx.user.id, input.period);
+    }),
+});