Allow omitting limit to return all candles in range

Change default limit from 100 to None. When limit is omitted,
EDM returns all candles in the requested range without truncation.

Also increased max limit from 1000 to 10000 for large requests.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/exchange_data_manager/api/rest.py

@@ -283,7 +283,7 @@ async def get_candles(
     timeframe: str = Query(..., description="Candle timeframe (e.g., 5m, 1h)"),
     start: Optional[int] = Query(None, description="Start timestamp (Unix seconds)"),
     end: Optional[int] = Query(None, description="End timestamp (Unix seconds)"),
-    limit: Optional[int] = Query(100, description="Maximum candles to return", le=1000),
+    limit: Optional[int] = Query(None, description="Maximum candles to return (omit for all)", le=10000),
     session_id: Optional[str] = Query(
         None,
         description="Optional session ID for per-session exchange credentials",

src/exchange_data_manager/cache/manager.py

@@ -189,6 +189,20 @@ class CacheManager:
             source = "exchange" if exchange_candles else "memory"
             return result, source
 
+        # Step 2b: Handle SINCE mode (start provided, no end)
+        # Gaps with end=None need to be fetched from exchange directly
+        import time as time_module
+        now = int(time_module.time())
+        normalized_gaps = []
+        for gap_start, gap_end in gaps_to_fill:
+            if gap_start is not None and gap_end is None:
+                # SINCE mode: fetch from start to now
+                normalized_gaps.append((gap_start, now))
+            elif gap_start is not None and gap_end is not None:
+                normalized_gaps.append((gap_start, gap_end))
+            # Skip gaps where start is None (shouldn't happen with proper request)
+        gaps_to_fill = normalized_gaps if normalized_gaps else gaps_to_fill
+
         db_hit = False
         exchange_hit = False