rename(phase 1): CapaKraken → Nexus across code, UI, docs, CI

- @capakraken/* → @nexus/* across 12 packages (root + 11 workspaces),
  1551 import lines migrated via codemod
- User-visible brand strings renamed (emails, page titles, PWA
  manifest, mobile header, MFA backup-codes header, tooltips, signin
  page, invite page, weekly digest, install prompt)
- TOTP issuer "CapaKraken" → "Nexus" (existing secrets still valid;
  re-enrollment relabels them in users' authenticator apps)
- Function rename: assertCapaKrakenDbTarget → assertNexusDbTarget
- LocalStorage migration shim in apps/web/src/app/layout.tsx copies
  capakraken_* → nexus_* on first load (guarded by nexus_migrated_v1
  sentinel; runs once per browser, then never again)
- Service-worker cache name capakraken-v2 → nexus-v2 with one-time
  caches.delete('capakraken-v2') from the same shim
- Email-domain fixtures @capakraken.{dev,app} → @nexus.{dev,app} in
  seed data, e2e specs, SMTP default fallback
- Dockerfile.dev / Dockerfile.prod / all .github/workflows/*.yml
  pnpm --filter @capakraken/* → @nexus/*
- README, CLAUDE.md, LEARNINGS.md, all docs/*.md, .env.example,
  tooling/deploy/.env.production.example brand sweep

Phase 1 deliberately leaves untouched (handled in Phase 3 cutover):
- PostgreSQL DB name "capakraken" and POSTGRES_USER "capakraken"
- Volume names capakraken_pgdata etc.
- Compose project name "capakraken" / "capakraken-prod"
- db-target-guard default expectedDatabase
- env-var CAPAKRAKEN_EXPECTED_DB_NAME
- Container DNS names in docker-compose.ci.yml

Quality gates green: pnpm typecheck (7/7), pnpm test:unit (7/7),
pnpm lint (0 errors), check:exports/imports/architecture all pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

packages/engine/src/__tests__/availability.test.ts

@@ -1,4 +1,4 @@
-import { AllocationStatus } from "@capakraken/shared";
+import { AllocationStatus } from "@nexus/shared";
 import { describe, expect, it } from "vitest";
 import { detectOverlaps, validateAvailability } from "../allocation/availability-validator.js";
 
@@ -24,12 +24,14 @@ describe("validateAvailability", () => {
   });
 
   it("detects conflict when combined hours exceed availability", () => {
-    const existing = [{
-      startDate: new Date("2025-01-06"),
-      endDate: new Date("2025-01-10"),
-      hoursPerDay: 6,
-      status: AllocationStatus.CONFIRMED,
-    }];
+    const existing = [
+      {
+        startDate: new Date("2025-01-06"),
+        endDate: new Date("2025-01-10"),
+        hoursPerDay: 6,
+        status: AllocationStatus.CONFIRMED,
+      },
+    ];
 
     const result = validateAvailability(
       new Date("2025-01-06"),
@@ -44,12 +46,14 @@ describe("validateAvailability", () => {
   });
 
   it("passes when combined hours exactly match availability", () => {
-    const existing = [{
-      startDate: new Date("2025-01-06"),
-      endDate: new Date("2025-01-10"),
-      hoursPerDay: 4,
-      status: AllocationStatus.CONFIRMED,
-    }];
+    const existing = [
+      {
+        startDate: new Date("2025-01-06"),
+        endDate: new Date("2025-01-10"),
+        hoursPerDay: 4,
+        status: AllocationStatus.CONFIRMED,
+      },
+    ];
 
     const result = validateAvailability(
       new Date("2025-01-06"),
@@ -63,12 +67,14 @@ describe("validateAvailability", () => {
   });
 
   it("ignores cancelled allocations", () => {
-    const existing = [{
-      startDate: new Date("2025-01-06"),
-      endDate: new Date("2025-01-10"),
-      hoursPerDay: 8,
-      status: AllocationStatus.CANCELLED,
-    }];
+    const existing = [
+      {
+        startDate: new Date("2025-01-06"),
+        endDate: new Date("2025-01-10"),
+        hoursPerDay: 8,
+        status: AllocationStatus.CANCELLED,
+      },
+    ];
 
     const result = validateAvailability(
       new Date("2025-01-06"),
@@ -105,11 +111,9 @@ describe("detectOverlaps", () => {
   };
 
   it("detects overlapping allocations", () => {
-    const overlaps = detectOverlaps(
-      new Date("2025-01-08"),
-      new Date("2025-01-15"),
-      [existingAlloc],
-    );
+    const overlaps = detectOverlaps(new Date("2025-01-08"), new Date("2025-01-15"), [
+      existingAlloc,
+    ]);
     expect(overlaps).toContain("alloc-1");
   });
 
@@ -134,11 +138,7 @@ describe("detectOverlaps", () => {
 
   it("ignores cancelled allocations", () => {
     const cancelled = { ...existingAlloc, status: AllocationStatus.CANCELLED };
-    const overlaps = detectOverlaps(
-      new Date("2025-01-08"),
-      new Date("2025-01-15"),
-      [cancelled],
-    );
+    const overlaps = detectOverlaps(new Date("2025-01-08"), new Date("2025-01-15"), [cancelled]);
     expect(overlaps).toHaveLength(0);
   });
 });