diff --git a/README.md b/README.md
index 50e68ad..4e56f2d 100644
--- a/README.md
+++ b/README.md
@@ -1,66 +1,31 @@
-# SupportHub API
+### Development
+- docker compose --env-file .env.development -f docker-compose.development.yml up -d --build
 
-### Development (Docker)
-- Start all services: `docker compose --env-file .env.development -f docker-compose.development.yml up -d --build`
-- Start only database & cache (for local app development): `docker compose --env-file .env.development -f docker-compose.development.yml up -d postgres redis`
+### Test
+- docker compose --env-file .env.test -f docker-compose.test.yml up --build
 
-### Test (Docker)
-- `docker compose --env-file .env.test -f docker-compose.test.yml up --build`
+### Production
+- docker compose --env-file .env.prod -f docker-compose.prod.yml up --build -d
 
-### Production (Docker)
-- `docker compose --env-file .env.prod -f docker-compose.prod.yml up --build -d`
+### Stop
+- docker compose -f docker-compose.prod.yml down
 
-### Stop / Down
-- Stop production: `docker compose -f docker-compose.prod.yml down`
-- Stop development: `docker compose -f docker-compose.development.yml down`
-- Stop development & wipe volumes: `docker compose --env-file .env.development -f docker-compose.development.yml down -v`
+### List Containers
+- docker compose --env-file .env.development -f docker-compose.development.yml ps
 
-### List Containers & Logs
-- List containers: `docker compose --env-file .env.development -f docker-compose.development.yml ps`
-- Follow logs: `docker compose --env-file .env.development -f docker-compose.development.yml logs -f`
+### Logs
+- docker compose --env-file .env.development -f docker-compose.development.yml logs -f
 
----
-
-### Local Development (Host)
-1. Start database & cache in Docker:
-   ```bash
-   docker compose --env-file .env.development -f docker-compose.development.yml up -d postgres redis
-   ```
-2. Start API server in watch mode:
-   ```bash
-   npm run dev
-   ```
-
----
-
-### Database Migrations & Prisma
-
-- **Generate Prisma Client**:
-  ```bash
-  npm run prisma:generate
-  ```
-
-- **Run / Apply Dev Migrations**:
-  ```bash
-  npx dotenv-cli -e .env.development -- npm run prisma:migrate
-  ```
-
-- **Deploy Migrations (Production/CI)**:
-  ```bash
-  npx dotenv-cli -e .env.development -- npm run prisma:deploy
-  ```
-
-- **Push Schema directly (Sync schema without migration files)**:
-  ```bash
-  npx dotenv-cli -e .env.development -- npx prisma db push
-  ```
-
----
+### Database Migrations
+- **Local (using .env.development):**
+  - Create/apply new migration: `npx prisma migrate dev --name <name>`
+  - Push schema directly (prototype/sync): `npx prisma db push`
+  - Deploy pending migrations: `npm run prisma:deploy`
+- **Inside Docker Container:**
+  - `docker exec -it support-api-development npx prisma migrate deploy`
 
 ### Database Seeding
-
-- **Seed Database (Roles, Products, Categories, Hierarchy & Demo data)**:
-  ```bash
-  npx dotenv-cli -e .env.development -- npm run prisma:seed
-  ```
-
+- **Local:**
+  - `npm run prisma:seed` (or `npx tsx --env-file=.env.development prisma/seed/index.ts`)
+- **Inside Docker Container:**
+  - `docker exec -it support-api-development npm run prisma:seed`
diff --git a/src/modules/orchestration/escalation/repository/escalation-event.repository.ts b/src/modules/orchestration/escalation/repository/escalation-event.repository.ts
index 120c8f7..6d5ee39 100644
--- a/src/modules/orchestration/escalation/repository/escalation-event.repository.ts
+++ b/src/modules/orchestration/escalation/repository/escalation-event.repository.ts
@@ -10,13 +10,51 @@ export interface CreateEscalationEventData {
   triggeredBy: string;
 }
 
+export interface CreateEscalationEventResult {
+  event: EscalationEvent;
+  /** False when `create` returned a pre-existing event instead of inserting a new one — the
+   * caller (EscalationService.fire) uses this to skip re-running side effects (reassignment,
+   * the audit event-bus publish) for a duplicate trigger. */
+  wasNewlyCreated: boolean;
+}
+
+function isDuplicateRuleEscalationConflict(error: unknown): boolean {
+  return (
+    error instanceof Prisma.PrismaClientKnownRequestError &&
+    error.code === 'P2002' &&
+    (error.meta?.target as string[] | undefined)?.includes('ruleId') === true
+  );
+}
+
 export class EscalationEventRepository {
   constructor(private readonly prisma = prismaClient) {}
 
-  async create(data: CreateEscalationEventData): Promise<EscalationEvent> {
-    return this.prisma.escalationEvent.create({
-      data: data as Prisma.EscalationEventUncheckedCreateInput,
-    });
+  /**
+   * 016-load-concurrency-testing research.md §3: a rule-triggered escalation
+   * (`data.ruleId` set) can only ever legitimately fire once per ticket over that ticket's
+   * lifetime (SLARun.ticketId is @unique — no reopen-cycle support). The
+   * `escalation_events_ticket_rule_unique` partial unique index (migration 20260909120000)
+   * enforces this at the database level; a duplicate trigger (e.g. two overlapping breach-sweep
+   * passes, or a re-delivered job) fails with `P2002` here, and this method returns the
+   * pre-existing event instead of throwing — the duplicate is silently absorbed, never
+   * surfaced as an error to a caller that did nothing wrong. Manual escalations (`ruleId: null`)
+   * are unaffected and always insert a new row.
+   */
+  async create(data: CreateEscalationEventData): Promise<CreateEscalationEventResult> {
+    try {
+      const event = await this.prisma.escalationEvent.create({
+        data: data as Prisma.EscalationEventUncheckedCreateInput,
+      });
+      return { event, wasNewlyCreated: true };
+    } catch (error) {
+      if (!isDuplicateRuleEscalationConflict(error)) throw error;
+
+      const existing = await this.prisma.escalationEvent.findFirst({
+        where: { ticketId: data.ticketId, ruleId: data.ruleId },
+      });
+      if (!existing) throw error; // conflict raced with a delete — surface the original error.
+      return { event: existing, wasNewlyCreated: false };
+    }
   }
 
   async findAllForTicket(ticketId: string): Promise<EscalationEvent[]> {
diff --git a/src/modules/orchestration/escalation/service/escalation.service.ts b/src/modules/orchestration/escalation/service/escalation.service.ts
index 667c32b..be79de5 100644
--- a/src/modules/orchestration/escalation/service/escalation.service.ts
+++ b/src/modules/orchestration/escalation/service/escalation.service.ts
@@ -76,7 +76,7 @@ export class EscalationService {
     actor: string,
     reason: string,
   ): Promise<EscalationEvent> {
-    const event = await this.events.create({
+    const { event, wasNewlyCreated } = await this.events.create({
       ticketId,
       ruleId,
       // No existing model persists "which hierarchy node is this ticket currently in" — Assignment
@@ -88,6 +88,12 @@ export class EscalationService {
       triggeredBy: actor,
     });
 
+    // 016-load-concurrency-testing research.md §3/FR-003: a duplicate rule-triggered trigger
+    // (the repository already detected and absorbed it) must not also reassign or re-publish —
+    // both already happened for the winning attempt; doing them again would be the exact
+    // duplicate-side-effect bug this feature exists to close.
+    if (!wasNewlyCreated) return event;
+
     await this.assignments.assignToSpecificNode(ticketId, targetNodeId, actor, reason);
 
     // research.md "SLA_BREACHED/ESCALATION_TRIGGERED are also published, for audit, not for