feat req: additional features for our `lib`

[mdvsh]

initial brain dump:

HashMap (for URL deduping, index)
Vector (for posting lists)
PriorityQueue (for crawler frontier)
ThreadSafeQueue (for crawler worker pools)

subsequent thinking: (may or may not be reqd)

Memory Management:

Object Pool (for small objects)
Arena Allocator (for variable size)

Specialized Containers:

BitSet (for compression/flags)
Trie (URL/dictionary)
Bloom Filter (quick testing)
String View (zero-copy)
Lock-free Queue

IO/Streaming:

Buffered Input/Output
Ring Buffers
Stream Interfaces

String Processing:

UTF-8 Support
String Interning
Rope Structure
String View

Concurrency:

Read-Write Locks
Thread Pool
Barrier Synchronization
Event System

Error Handling:

Expected Template
Error Categories
Status Codes

Algorithms:

Quick Select
Rolling Hash
Edit Distance
Multi-way Merge

Debug Support:

Logging Framework
Performance Counters
Memory Tracking

Network:

URL Parser
Connection Pool
Protocol Handlers