feat: book commenting system with upvote/downvote + fix profile SSR crash

- Add book_comments and comment_votes PocketBase collections (pb-init.sh + pocketbase.go EnsureCollections)
- Web: CommentsSection.svelte with post form, vote buttons, lazy-loaded per-book
- API routes: GET/POST /api/comments/[slug], POST /api/comments/[id]/vote
- iOS: BookComment + CommentsResponse models, fetchComments/postComment/voteComment in APIClient, CommentsView + CommentsViewModel wired into BookDetailView
- Fix profile page SSR crash (ERR_MODULE_NOT_FOUND cropperjs): lazy-load AvatarCropModal via dynamic import guarded by browser, move URL.createObjectURL into onMount

scraper/internal/storage/pocketbase.go

@@ -16,6 +16,9 @@
 //	                 started(date), finished(date), error_message(text)
 //	user_sessions  — user_id(text), session_id(text,unique), user_agent(text),
 //	                 ip(text), created_at(date), last_seen(date)
+//	book_comments  — slug(text), user_id(text), username(text), body(text),
+//	                 upvotes(number), downvotes(number), created(date)
+//	comment_votes  — comment_id(text), user_id(text), session_id(text), vote(text: up|down)
 package storage
 
 import (
@@ -422,6 +425,29 @@ func (s *PocketBaseStore) EnsureCollections(ctx context.Context) error {
 				{"name": "last_seen", "type": "date"},
 			},
 		},
+		{
+			"name": "book_comments",
+			"type": "base",
+			"fields": []map[string]interface{}{
+				{"name": "slug", "type": "text", "required": true},
+				{"name": "user_id", "type": "text"},
+				{"name": "username", "type": "text"},
+				{"name": "body", "type": "text", "required": true},
+				{"name": "upvotes", "type": "number"},
+				{"name": "downvotes", "type": "number"},
+				{"name": "created", "type": "date"},
+			},
+		},
+		{
+			"name": "comment_votes",
+			"type": "base",
+			"fields": []map[string]interface{}{
+				{"name": "comment_id", "type": "text", "required": true},
+				{"name": "user_id", "type": "text"},
+				{"name": "session_id", "type": "text", "required": true},
+				{"name": "vote", "type": "text", "required": true}, // "up" | "down"
+			},
+		},
 	}
 	for _, col := range collections {
 		name, _ := col["name"].(string)