Add five new slice manipulation functions with tests, examples, and documentation.

New Functions

Take

Safely takes the first n elements from a slice. Handles edge cases and creates a copy to avoid mutating the original.

Production use cases:

• Pagination: Get first page of results
• Top N items: Extract top 10 users, products, or metrics
• Batch processing: Process first 100 tasks from queue

TakeWhile

Takes elements from the beginning while the predicate returns true. Useful for processing ordered data until a condition is met.

Production use cases:

• Process successful transactions until first failure
• Parse valid tokens until first invalid one

FilterTake

Filters elements and takes the first n matches. More efficient than chaining Filter and Take, as it stops after finding n matches.

Production use cases:

• Search: Find first 5 active users (stops early, doesn't scan entire list)

Window

Creates overlapping sliding windows of a given size (step=1). Each window overlaps with the previous one by size-1 elements.

Production use cases:

• Time series analysis: Calculate 7-day moving averages
• Anomaly detection: Compare adjacent time periods

Sliding

Creates sliding windows with configurable step size. More flexible than Window - can create overlapping or non-overlapping windows.

Production use cases:

• Batch processing: Process data in chunks (step=size, like Chunk)
• Aggregation: Calculate averages over 5-minute windows with 1-minute steps
• Sampling: Extract every 10th element in batches