feat: implement user profiles with achievements and primary badge system (#58)

## Summary

This PR implements comprehensive user profile enhancements including:
- User profile pages showing stats, badges, social links, and bio
- Achievement system with 62 achievements across 5 categories
- Primary badge selection allowing users to display their preferred badge
- Admin profile editing capabilities

## Changes

### User Profiles (#45)
- **Frontend**: User profile pages with stats display
  - Profile cards showing avatar, display name, username, and bio
  - Social links section (Website, GitHub, Bluesky, LinkedIn, Twitch, YouTube, Discord)
  - Stats display (suggestions, accepted suggestions, likes, comments)
  - Recent achievements section
  - Badge display
  - Report button for other users' profiles
- **Backend**: Profile API endpoints
  - Get user profile by username or ID
  - Profile includes stats, badges, and achievement points

### Achievement System (#48)
- **Database**: UserAchievement model for tracking progress
- **62 Total Achievements** across 5 categories:
  - **Suggestions (15)**: First suggestion through ultimate curator
  - **Likes (12)**: First like through legendary fan
  - **Comments (12)**: First comment through review legend
  - **Engagement (15)**: Login streaks and activity milestones
  - **Reports (8)**: Valid reports and accuracy tracking
- **Backend**: AchievementService with real-time checking
  - Integrated into all user interaction points
  - API endpoints for achievement data
  - Progress tracking to avoid recalculation
- **Frontend**: Achievements page and profile integration
  - Full achievements page with category filtering
  - Tier-based styling (Bronze, Silver, Gold, Platinum, Diamond)
  - Progress indicators for in-progress achievements
  - Recent achievements on profile pages

### Primary Badge System (#49)
- **Database**: Add primaryBadge field to User model
- **Backend**: Update profile endpoints to include primary badge
- **Frontend**: Primary badge selection in settings
  - Only shows badges the user has earned
  - Displayed on profile page
  - Displayed in comments (next to username)
  - Falls back to no badge if selection is invalid
- **Admin Features**: Admin can edit any user's primary badge

### Admin Enhancements
- Comprehensive profile editing modal for admins
  - Edit display name, bio, slug, social links
  - Set primary badge for users
  - Visual feedback for save/error states
- Admin action buttons in report review modals
  - Ban user, delete comment, edit profile
  - Integrated with report workflow

### Quality Improvements
- Improved dropdown option contrast for readability
- Hide all badges when no primary badge is selected
- "View All" achievements link only shown on own profile
- Improved achievement text readability

## Testing

- ✅ User profiles display correctly with stats and badges
- ✅ Achievement checking works for all interaction types
- ✅ Primary badge selection persists and displays correctly
- ✅ Admin profile editing saves successfully
- ✅ Report workflow integrated with admin actions
- ✅ Achievements page shows all 62 achievements with filtering
- ✅ Text readability improved across components

Closes #45
Closes #48
Closes #49

Co-authored-by: Hikari <hikari@nhcarrigan.com>
Reviewed-on: #58
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

api/src/app/routes/achievements/index.ts

@@ -0,0 +1,122 @@
+/**
+ * @copyright 2026 NHCarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import type { FastifyPluginAsync } from "fastify";
+import {
+  ACHIEVEMENT_LIST,
+  ACHIEVEMENTS,
+  AchievementProgress,
+  UserAchievementSummary,
+} from "@library/shared-types";
+import { AchievementService } from "../../services/achievement.service";
+
+const achievementsRoutes: FastifyPluginAsync = async (app) => {
+  const achievementService = new AchievementService();
+
+  /**
+   * Get all achievement definitions (public route).
+   */
+  app.get("/definitions", async () => {
+    return ACHIEVEMENT_LIST;
+  });
+
+  /**
+   * Get a specific achievement definition by key (public route).
+   */
+  app.get<{ Params: { key: string } }>(
+    "/definitions/:key",
+    async (request, reply) => {
+      const { key } = request.params;
+      const achievement = ACHIEVEMENTS[key];
+
+      if (!achievement) {
+        return reply.notFound("Achievement not found");
+      }
+
+      return achievement;
+    },
+  );
+
+  /**
+   * Get current user's achievement summary (authenticated users).
+   */
+  app.get<{ Reply: UserAchievementSummary }>(
+    "/summary",
+    {
+      preValidation: [app.authenticate],
+    },
+    async (request) => {
+      const userId = request.user.id;
+      const summary = await achievementService.getUserAchievementSummary(
+        userId,
+      );
+      return summary;
+    },
+  );
+
+  /**
+   * Get current user's achievement progress (authenticated users).
+   */
+  app.get<{ Reply: AchievementProgress[] }>(
+    "/progress",
+    {
+      preValidation: [app.authenticate],
+    },
+    async (request) => {
+      const userId = request.user.id;
+      const progress = await achievementService.getUserAchievementProgress(
+        userId,
+      );
+      return progress;
+    },
+  );
+
+  /**
+   * Get another user's achievement summary by ID (authenticated users).
+   */
+  app.get<{ Params: { userId: string }; Reply: UserAchievementSummary }>(
+    "/users/:userId/summary",
+    {
+      preValidation: [app.authenticate],
+    },
+    async (request, reply) => {
+      const { userId } = request.params;
+
+      try {
+        const summary = await achievementService.getUserAchievementSummary(
+          userId,
+        );
+        return summary;
+      } catch (error) {
+        return reply.notFound("User not found");
+      }
+    },
+  );
+
+  /**
+   * Get another user's achievement progress by ID (authenticated users).
+   */
+  app.get<{ Params: { userId: string }; Reply: AchievementProgress[] }>(
+    "/users/:userId/progress",
+    {
+      preValidation: [app.authenticate],
+    },
+    async (request, reply) => {
+      const { userId } = request.params;
+
+      try {
+        const progress = await achievementService.getUserAchievementProgress(
+          userId,
+        );
+        return progress;
+      } catch (error) {
+        return reply.notFound("User not found");
+      }
+    },
+  );
+};
+
+export default achievementsRoutes;