refactor: deduplicate modals, notifications, confirms, comboboxes, proficiency

Modal Overlay (Finding 1 — 6 admin files):
- Migrated CountriesClient, ManagementLevelsClient, OrgUnitsClient,
  CalculationRulesClient, UtilizationCategoriesClient, RoleModal
  from inline fixed-overlay to AnimatedModal component
- Gains: animated transitions, backdrop blur, escape key for free

Notification Helper (Finding 9 — 9 API files, 14 call sites):
- New createNotification() + createNotificationsForUsers() in
  packages/api/src/lib/create-notification.ts
- Handles exactOptionalPropertyTypes spread + SSE emit internally
- Simplified: budget-alerts, estimate-reminders, auto-staffing,
  vacation-conflicts, chargeability-alerts, comment, vacation, notification

ConfirmDialog (Finding 3 — 11 files):
- Replaced all window.confirm() calls with ConfirmDialog component
- Files: CommentThread, EffortRules, ExperienceMultipliers,
  ManagementLevels, CalculationRules, Countries, RateCards,
  ApplyEffortRules, ApplyExperienceMultipliers, NotificationCenter,
  ReminderModal

EntityCombobox (Finding 4 — 3 files):
- New generic EntityCombobox<T> with customization hooks
- ResourceCombobox + ProjectCombobox rewritten as thin wrappers
- All consumers unchanged (backwards-compatible props)

Proficiency Constants (Finding 2 — 2 files):
- SkillsAnalytics + SkillMarketplace now import from skills/shared.tsx
- Deleted ~70 LOC of local duplicate definitions

Regression: 283 engine + 37 staffing tests pass. TypeScript clean.
AI Assistant: all 87 tools verified accessible.

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

packages/api/src/router/comment.ts

@@ -2,7 +2,7 @@ import { z } from "zod";
 import { TRPCError } from "@trpc/server";
 import { SystemRole } from "@planarchy/shared";
 import { createTRPCRouter, protectedProcedure } from "../trpc.js";
-import { emitNotificationCreated } from "../sse/event-bus.js";
+import { createNotification } from "../lib/create-notification.js";
 
 // ─── Helpers ──────────────────────────────────────────────────────────────────
 
@@ -138,22 +138,20 @@ export const commentRouter = createTRPCRouter({
           input.body.length > 120 ? `${input.body.slice(0, 120)}...` : input.body;
 
         await Promise.all(
-          mentionedUserIds.map(async (userId) => {
-            const notification = await ctx.db.notification.create({
-              data: {
-                userId,
-                type: "COMMENT_MENTION",
-                title: `${authorName} mentioned you in a comment`,
-                body: truncatedBody,
-                entityId: input.entityId,
-                entityType: input.entityType,
-                senderId: authorId,
-                link: `/estimates/${input.entityId}?tab=comments`,
-                channel: "in_app",
-              },
-            });
-            emitNotificationCreated(userId, notification.id);
-          }),
+          mentionedUserIds.map((userId) =>
+            createNotification({
+              db: ctx.db,
+              userId,
+              type: "COMMENT_MENTION",
+              title: `${authorName} mentioned you in a comment`,
+              body: truncatedBody,
+              entityId: input.entityId,
+              entityType: input.entityType,
+              senderId: authorId,
+              link: `/estimates/${input.entityId}?tab=comments`,
+              channel: "in_app",
+            }),
+          ),
         );
       }