feat: Nearshore-Ratio indicator per project

Engine (packages/engine):
- calculateShoringRatio() pure function: onshore/offshore hours,
  country breakdown, threshold check, weighted by hours not headcount
- 12 unit tests: empty, 100% onshore/offshore, mixed ratios,
  custom threshold, case-insensitive, unknown country, FTE weighting

Schema:
- Project.shoringThreshold (default 55%) — per-project configurable
- Project.onshoreCountryCode (default "DE") — configurable onshore country

API (project router):
- getShoringRatio query: loads assignments with resource.country,
  computes ratio, returns full breakdown
- update mutation: accepts shoringThreshold + onshoreCountryCode

UI:
- ShoringIndicator: stacked horizontal bar with country segments,
  severity badge (green/yellow/red), hover tooltip, dark theme
- ShoringBadge: mini colored dot + % for project list column
- ProjectModal: "Max Offshore %" number input
- Project detail: indicator after budget status card
- Project list: "Shoring" column (default hidden, toggleable)

AI Assistant:
- get_shoring_ratio tool: human-readable breakdown with threshold alert

Colors: green (<threshold-10), yellow (threshold-10 to threshold), red (>=threshold)
Default: 55% offshore threshold, "DE" as onshore country

Co-Authored-By: claude-flow <ruv@ruv.net>

packages/db/prisma/schema.prisma

@@ -812,7 +812,9 @@ model Project {
   startDate       DateTime       @db.Date
   endDate         DateTime       @db.Date
   status          ProjectStatus  @default(DRAFT)
-  responsiblePerson String?
+  responsiblePerson  String?
+  shoringThreshold   Int?              @default(55)  // Max offshore % before alert (0-100)
+  onshoreCountryCode String?           @default("DE") // Country code considered "onshore"
   color             String?           // Hex color for timeline display, e.g. "#3b82f6"
   coverImageUrl     String?  @db.Text // Base64 data-URL for project cover art
   coverFocusY       Int      @default(50) // Vertical focus point 0-100 (% from top)