feat: integrate hunos web server + jwt-nim-baraba + real WAL recovery + compaction

HTTP Server:
- Replaced asynchttpserver with hunos (multi-threaded, trie router, CORS middleware)
- JWT authentication via jwt-nim-baraba (HS256 with BearSSL crypto)
- POST /query, GET /health, GET /metrics, POST /auth, GET /api (OpenAPI spec)
- Proper CORS headers via hunos corsMiddleware

WAL Recovery:
- recover() now actually applies committed entries (REDO)
- Skips uncommitted entries (UNDO)
- Takes optional LSMTree parameter to apply recovery

SSTable Compaction:
- Real compaction: reads SSTable entries, merges by key (newest wins), writes merged file
- Deduplication: keeps only newest version per key
- Tombstone cleanup: removes deleted entries
- Old SSTable files deleted after merge

Dependencies:
- Added hunos >= 1.2.0 and jwt >= 2.1.0 to nimble

SSTable fields exported for compaction access.

All 216 tests pass

src/barabadb/storage/lsm.nim

@@ -31,13 +31,13 @@ type
 
   SSTable* = object
     path*: string
-    index: Table[string, int64]  # key -> file offset in data block
-    bloom: BloomFilter
-    level: int
-    minKey: string
-    maxKey: string
-    entryCount: int
-    mmapFile: MmapFile
+    index*: Table[string, int64]
+    bloom*: BloomFilter
+    level*: int
+    minKey*: string
+    maxKey*: string
+    entryCount*: int
+    mmapFile*: MmapFile
 
   LSMTree* = ref object
     dir: string