fix: resolve banned term false positives and show server error in frontend

- Exact match now uses word boundaries (\b) instead of substring to prevent
  'ero' matching 'hero', 'joi' matching 'join'
- Fuzzy match threshold raised from <=4 to <=5 chars to skip short words
- Added 'gooning' to fuzzy skip list ('cooling' matched it at distance 2)
- Removed 'join' from banned_terms.txt (legitimate word)
- Frontend now reads err.response.data.error to display server messages
- Error message for blocked searches: 'Unable to query — banned search term detected.'

web/server/banned_terms.txt

@@ -117,7 +117,6 @@ high protein milk
 
 # JOI
 joi
-join
 countdown
 
 # ASMR

web/server/routes/search.py

@@ -59,20 +59,27 @@ def _is_banned(query: str) -> bool:
         _load_banned_terms()
     query_lower = query.lower()
 
-    # Exact match check
+    # Exact match check (word-boundary aware to avoid "hero" matching "ero", etc.)
     for term in _banned_terms:
-        if term in query_lower:
+        if re.search(r'\b' + re.escape(term) + r'\b', query_lower):
+            return True
+    # Multi-word exact match (e.g. "no nut november") — substring OK for phrases
+    for term in _banned_terms:
+        if ' ' in term and term in query_lower:
             return True
 
     # Fuzzy match check for words in the query
     query_words = query_lower.split()
     for word in query_words:
-        # Skip short words (4 chars or less) to avoid false positives (e.g. "lofi" matching "loli")
-        if len(word) <= 4:
+        # Skip short words (5 chars or less) to avoid false positives (e.g. "hero" matching "ero")
+        if len(word) <= 5:
             continue
         for term in _banned_terms:
             # Skip fuzzy matching for short banned terms (too many false positives)
-            if len(term) <= 4:
+            if len(term) <= 5:
+                continue
+            # Skip fuzzy matching for terms that cause false positives
+            if term in ("strip", "gooning"):
                 continue
             # Only fuzzy match for terms with similar length
             if abs(len(word) - len(term)) > 2:
@@ -122,7 +129,7 @@ def search():
             return make_error_response("Page must be greater than 0", 400)
 
         if _is_banned(query):
-            return make_error_response("This search is not allowed. Please choose different keywords.", 400)
+            return make_error_response("Unable to query — banned search term detected.", 400)
 
         sanitized_query = re.sub(r'[^\w\s\-\'"\.]+', "", query)
         search_query = f"ytsearch{limit * page}:{sanitized_query}"

web/web-app/src/pages/SearchPage.tsx

@@ -79,7 +79,7 @@ export default function SearchPage() {
         setHasMore(response.hasMore);
         return response;
       } catch (err: any) {
-        setError(err.message || "Failed to search videos. Please try again.");
+        setError(err.response?.data?.error || err.message || "Failed to search videos. Please try again.");
         console.error("Search error:", err);
         return null;
       }