Problem

PhysicalAIAVDatasetLocalInterface.__init__ in src/alpamayo_r1/data/pai_utils.py accepts a wider variety of chunk_ids inputs than its annotation and docstring suggest:

• The annotation is list[int] | None, but the body has explicit branches for str (range form), int (single id), and any iterable. Static checkers reject the documented "0-9" range usage outright.

• The docstring reads:

  chunk_ids: List of chunk IDs to load, or a range string (e.g. "0-9").

  …without spelling out whether the end is inclusive. The implementation does range(chunk_start, chunk_end), which is exclusive of the end — matching the semantics in scripts/download_pai.py (called out explicitly in Accept multiple --chunk-ids without quoting in download_pai.py #81) and scripts/curate_pai_samples.py (made explicit in Document exclusive-end --chunk range in curate_pai_samples.py #87). A user reading the example "0-9" would reasonably guess "0..9 inclusive" and silently lose chunk 9.

Fix

Pure docs + annotation. No runtime behavior change.

• Broaden the type hint to list[int] | tuple[int, ...] | int | str | None, matching the actual isinstance branches in the body.
• Replace the one-line docstring with a bullet list of accepted forms, spell out the exclusive-end semantics with a worked example ("0-10" → chunks 0..9), and cross-reference the two scripts that share the convention so they stay in lockstep with Accept multiple --chunk-ids without quoting in download_pai.py #81 and Document exclusive-end --chunk range in curate_pai_samples.py #87.

Verification

The new annotation accepts every concrete shape the body's isinstance chain handles. Range example matches the existing implementation (range(chunk_start, chunk_end)).