* [BugFix] Reject contracting shared-buffer layouts in T.annotate_layout
T.annotate_layout could accept a contracting many-to-one forward map on a
shared buffer. makeBufferWithLayout then misread the smaller output extent as
a replication factor, rewrote the buffer to a higher rank, and eventually
failed with an unrelated BufferStore dimensionality ICHECK.
Add a pigeonhole check for static layout shapes before the replication branch.
When the layout output extent is smaller than its input extent, raise a
user-facing ValueError that identifies the buffer and reports both extents.
Keep identity, permutation, and output-growing layouts unchanged.
This check intentionally targets contracting maps; general injectivity
analysis for maps with larger output bounding boxes is outside this change.
Fixes#2632
* [Layout] Enforce injective shared-buffer annotations
Add a LayoutNode injectivity check with an exact fallback for static domains, and reuse it for FragmentNode thread and replication coordinates. Validate shared-buffer annotations after layout reshaping so sparse many-to-one maps are rejected with a useful collision diagnostic while padded injective maps remain valid.
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Co-authored-by: LeiWang1999 <leiwang1999@outlook.com>
