fix: address PR review feedback

- Remove TDD section comment as requested
- Extract SECONDS_PER_DAY constant (86400.0) to global variable
- Fix docstring to reference vectorstore adapter instead of RedisVL directly

All single/two-letter variable expansion was already completed in previous commits.
Tests continue to pass after these cleanup changes.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: abrookins

agent_memory_server/long_term_memory.py

@@ -1363,16 +1363,15 @@ async def delete_long_term_memories(
     return await adapter.delete_memories(ids)
 
 
-# =========================
-# Recency scoring and forgetting helpers (pure functions for TDD)
-# =========================
+# Seconds per day constant for time calculations
+SECONDS_PER_DAY = 86400.0
 
 
 def _days_between(now: datetime, then: datetime | None) -> float:
     if then is None:
         return float("inf")
     delta = now - then
-    return max(delta.total_seconds() / 86400.0, 0.0)
+    return max(delta.total_seconds() / SECONDS_PER_DAY, 0.0)
 
 
 def score_recency(
@@ -1586,7 +1585,7 @@ async def forget_long_term_memories(
 ) -> dict:
     """Select and delete long-term memories according to policy.
 
-    Uses RedisVL via the vectorstore adapter to fetch candidates (empty query + filters),
+    Uses the vectorstore adapter to fetch candidates (empty query + filters),
     then applies `select_ids_for_forgetting` locally and deletes via adapter.
     """
     adapter = await get_vectorstore_adapter()