Add name suggestion engine with API endpoint and tests

Expand services/naming.py with suggest_names() that picks random words
from a category while excluding nicknames already used in the run. Add
GET /runs/{run_id}/name-suggestions?count=10 endpoint that reads the
run's naming_scheme and returns filtered suggestions. Includes 12 unit
tests covering selection, exclusion, exhaustion, and cross-category
independence.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/app/api/runs.py

@@ -19,7 +19,7 @@ from app.schemas.run import (
     RunResponse,
     RunUpdate,
 )
-from app.services.naming import get_naming_categories
+from app.services.naming import get_naming_categories, suggest_names
 
 router = APIRouter()
 
@@ -29,6 +29,31 @@ async def list_naming_categories():
     return get_naming_categories()
 
 
+@router.get("/{run_id}/name-suggestions", response_model=list[str])
+async def get_name_suggestions(
+    run_id: int,
+    count: int = 10,
+    session: AsyncSession = Depends(get_session),
+):
+    run = await session.get(NuzlockeRun, run_id)
+    if run is None:
+        raise HTTPException(status_code=404, detail="Run not found")
+
+    if not run.naming_scheme:
+        return []
+
+    # Collect nicknames already used in this run
+    result = await session.execute(
+        select(Encounter.nickname).where(
+            Encounter.run_id == run_id,
+            Encounter.nickname.isnot(None),
+        )
+    )
+    used_names = {row[0] for row in result}
+
+    return suggest_names(run.naming_scheme, used_names, count)
+
+
 @router.post("", response_model=RunResponse, status_code=201)
 async def create_run(data: RunCreate, session: AsyncSession = Depends(get_session)):
     # Validate game exists

backend/src/app/services/naming.py

@@ -1,4 +1,5 @@
 import json
+import random
 from functools import lru_cache
 from pathlib import Path
 
@@ -16,3 +17,29 @@ def _load_dictionary() -> dict[str, list[str]]:
 def get_naming_categories() -> list[str]:
     """Return sorted list of available naming category names."""
     return sorted(_load_dictionary().keys())
+
+
+def get_words_for_category(category: str) -> list[str]:
+    """Return the word list for a category, or empty list if not found."""
+    return _load_dictionary().get(category, [])
+
+
+def suggest_names(
+    category: str,
+    used_names: set[str],
+    count: int = 10,
+) -> list[str]:
+    """Pick random name suggestions from a category, excluding used names.
+
+    Returns up to `count` names. If the category is nearly exhausted,
+    returns fewer.
+    """
+    words = get_words_for_category(category)
+    if not words:
+        return []
+
+    available = [w for w in words if w not in used_names]
+    if not available:
+        return []
+
+    return random.sample(available, min(count, len(available)))