feat: base64 uploads, reusable forms, Discord roles, and UX improvements (#66)

## Summary

This PR includes multiple feature additions and fixes to improve the library application:

### 🎨 Base64 Image Upload Support
- Fixed Fastify body limit (1MB → 10MB) to accommodate base64-encoded images
- Corrected base64 size calculation and validation logic
- Improved error handling with proper 400 status codes and helpful messages
- Removed duplicate validation that was blocking uploads
- Users can now upload cover images up to 5MB (decoded size)

### 📝 Reusable Form Components
- Created 6 form components: `GameForm`, `BookForm`, `MusicForm`, `ShowForm`, `MangaForm`, `ArtForm`
- All forms support both 'add' and 'edit' modes with pre-population
- Integrated inline editing into all detail views (edit/delete buttons)
- Enhanced admin suggestions workflow with full forms instead of basic modals
- Added scroll-to-top when clicking edit in list views for better UX

### 🖼️ Default Cover Image
- Added beautiful library reading image as default cover for all media types
- Fixed static asset serving to use correct MIME types
- Updated all 12 components (6 list views + 6 detail views) to always show images

### 🔒 Tiered Rate Limiting
- Unauthenticated users: 100 requests/minute
- Authenticated users: 500 requests/minute (5x more lenient)
- Admin users: No rate limits (complete bypass via allowList)

### 🎮 Discord Integration
- Auto-assign library member role to users in NHCarrigan Discord server
- Checks server membership on every login
- Only assigns role if user is in server and doesn't have it yet
- Graceful error handling without blocking login
- Similar pattern to badge refresh flow

### 📚 Documentation
- Added comprehensive CLAUDE.md with:
  - Project structure and tech stack
  - Development workflow and commands
  - Database schema documentation
  - Authentication flow details
  - Security features
  - Code style conventions
  - Common gotchas and solutions

## Test Plan

- [x] Base64 image uploads work for cover images up to 5MB
- [x] Helpful error messages appear for validation failures
- [x] Edit/delete buttons appear on all detail views for admin users
- [x] Inline edit forms display and save correctly
- [x] Admin suggestions workflow uses full forms for all media types
- [x] Scroll-to-top works when editing from list views
- [x] Default cover image displays when no cover is provided
- [x] Static assets serve with correct MIME types
- [x] Rate limiting works correctly for different user types
- [x] Discord role assignment works on login
- [x] All builds pass without errors
- [x] No TypeScript errors

## Related Issues

Closes #65 - Base64 image upload issue

✨ This pull request was created with help from Hikari~ 🌸

Reviewed-on: #66
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/frontend/src/app/components/manga/manga-detail.component.ts

@@ -14,18 +14,28 @@ import { AuthService } from '../../services/auth.service';
 import { SanitizeService } from '../../services/sanitize.service';
 import { CommentDisplayComponent } from '../comment-display/comment-display.component';
 import { LikeButtonComponent } from '../shared/like-button.component';
-import { Manga, Comment, MangaStatus } from '@library/shared-types';
+import { MangaFormComponent } from '../shared/manga-form.component';
+import { Manga, Comment, MangaStatus, UpdateMangaDto } from '@library/shared-types';
 
 @Component({
   selector: 'app-manga-detail',
   standalone: true,
-  imports: [CommonModule, RouterLink, FormsModule, CommentDisplayComponent, LikeButtonComponent],
+  imports: [CommonModule, RouterLink, FormsModule, CommentDisplayComponent, LikeButtonComponent, MangaFormComponent],
   template: `
     <div class="container">
       <div class="breadcrumb">
         <a routerLink="/manga" class="breadcrumb-link">← Back to Manga</a>
       </div>
 
+      @if (showEditForm() && authService.user()?.isAdmin && manga()) {
+        <app-manga-form
+          mode="edit"
+          [manga]="manga()!"
+          (formSubmit)="saveEdit($event)"
+          (formCancel)="cancelEdit()"
+        ></app-manga-form>
+      }
+
       @if (loading()) {
         <div class="loading">Loading manga details...</div>
       } @else if (error()) {
@@ -36,11 +46,9 @@ import { Manga, Comment, MangaStatus } from '@library/shared-types';
         </div>
       } @else if (manga()) {
         <div class="manga-detail-card">
-          @if (manga()!.coverImage) {
-            <div class="manga-cover-section">
-              <img [src]="manga()!.coverImage" [alt]="manga()!.title" class="manga-cover-large">
-            </div>
-          }
+          <div class="manga-cover-section">
+            <img [src]="manga()!.coverImage || '/assets/default-cover.jpg'" [alt]="manga()!.title" class="manga-cover-large">
+          </div>
 
           <div class="manga-content">
             <div class="manga-header">
@@ -51,6 +59,12 @@ import { Manga, Comment, MangaStatus } from '@library/shared-types';
             </div>
 
             <p class="author">by {{ manga()!.author }}</p>
+            @if (authService.user()?.isAdmin) {
+              <div class="admin-actions">
+                <button (click)="toggleEditForm()" class="btn btn-edit">✏️ {{ showEditForm() ? 'Cancel Edit' : 'Edit' }}</button>
+                <button (click)="deleteManga()" class="btn btn-delete">🗑️ Delete</button>
+              </div>
+            }
 
             @if (manga()!.rating) {
               <div class="info-row">
@@ -296,6 +310,35 @@ import { Manga, Comment, MangaStatus } from '@library/shared-types';
       color: #4b5563;
     }
 
+
+    .admin-actions {
+      display: flex;
+      gap: 0.75rem;
+      margin-bottom: 1.5rem;
+      padding: 1rem;
+      background: #fef3c7;
+      border-radius: 4px;
+      border: 1px solid #fbbf24;
+    }
+
+    .btn-edit {
+      background: #3b82f6;
+      color: white;
+    }
+
+    .btn-edit:hover {
+      background: #2563eb;
+    }
+
+    .btn-delete {
+      background: #ef4444;
+      color: white;
+    }
+
+    .btn-delete:hover {
+      background: #dc2626;
+    }
+
     .info-row {
       display: flex;
       align-items: center;
@@ -495,7 +538,36 @@ import { Manga, Comment, MangaStatus } from '@library/shared-types';
         font-size: 1.5rem;
       }
 
-      .info-row {
+  
+    .admin-actions {
+      display: flex;
+      gap: 0.75rem;
+      margin-bottom: 1.5rem;
+      padding: 1rem;
+      background: #fef3c7;
+      border-radius: 4px;
+      border: 1px solid #fbbf24;
+    }
+
+    .btn-edit {
+      background: #3b82f6;
+      color: white;
+    }
+
+    .btn-edit:hover {
+      background: #2563eb;
+    }
+
+    .btn-delete {
+      background: #ef4444;
+      color: white;
+    }
+
+    .btn-delete:hover {
+      background: #dc2626;
+    }
+
+    .info-row {
         flex-direction: column;
         align-items: flex-start;
         gap: 0.25rem;
@@ -521,6 +593,7 @@ export class MangaDetailComponent implements OnInit {
   commentsLoading = signal(false);
   error = signal<string | null>(null);
   newCommentContent = '';
+  showEditForm = signal(false);
 
   ngOnInit() {
     const mangaId = this.route.snapshot.paramMap.get('id');
@@ -630,4 +703,45 @@ export class MangaDetailComponent implements OnInit {
       return `${hours} hour${hours === 1 ? '' : 's'} ${mins} minute${mins === 1 ? '' : 's'}`;
     }
   }
-}
+
+  toggleEditForm() {
+    this.showEditForm.update(value => !value);
+  }
+
+  saveEdit(data: UpdateMangaDto) {
+    const manga = this.manga();
+    if (!manga) return;
+
+    this.mangaService.updateManga(manga.id, data).subscribe({
+      next: (updatedManga) => {
+        this.manga.set(updatedManga);
+        this.showEditForm.set(false);
+      },
+      error: (err) => {
+        alert('Failed to update manga: ' + (err.error?.message || 'Unknown error'));
+      }
+    });
+  }
+
+  cancelEdit() {
+    this.showEditForm.set(false);
+  }
+
+  deleteManga() {
+    const manga = this.manga();
+    if (!manga) return;
+
+    if (!confirm(`Are you sure you want to delete "${manga.title}"? This action cannot be undone.`)) {
+      return;
+    }
+
+    this.mangaService.deleteManga(manga.id).subscribe({
+      next: () => {
+        this.router.navigate(['/manga']);
+      },
+      error: (err) => {
+        alert('Failed to delete manga: ' + (err.error?.message || 'Unknown error'));
+      }
+    });
+  }
+}