add remaining from_iter_unique methods

[sunshowers]

IdOrdMap had a from_iter_unique, but the other maps didn't. Add the remaining impls.

[Copilot]

Pull request overview

This PR adds from_iter_unique constructors to the remaining iddqd map types so callers can build maps from iterators while rejecting (rather than overwriting) the first detected conflict, matching the existing IdOrdMap::from_iter_unique behavior.

Changes:

• Added from_iter_unique inherent constructors for IdHashMap, BiHashMap, and TriHashMap that return DuplicateItem<T> on the first conflicting insertion.
• Refactored BiHashMap/TriHashMap insertion to share duplicate-detection logic that can return duplicate indexes for owned-error construction.
• Added integration tests covering success, empty iterators, and multi-key conflict reporting; updated the changelog.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/iddqd/src/id_hash_map/imp.rs	Adds IdHashMap::from_iter_unique implemented via the Entry API to return owned duplicates without T: Clone.
crates/iddqd/src/bi_hash_map/imp.rs	Adds BiHashMap::from_iter_unique and refactors insertion to expose duplicate indexes for owned error reporting.
crates/iddqd/src/tri_hash_map/imp.rs	Adds TriHashMap::from_iter_unique and refactors insertion similarly to support owned duplicate extraction.
crates/iddqd/tests/integration/id_hash_map.rs	Adds tests for IdHashMap::from_iter_unique (empty, success, duplicate error) and extends permutation proptest to cover the constructor.
crates/iddqd/tests/integration/bi_hash_map.rs	Adds tests for BiHashMap::from_iter_unique including single- vs multi-item duplicate reporting and extends permutation proptest coverage.
crates/iddqd/tests/integration/tri_hash_map.rs	Adds tests for TriHashMap::from_iter_unique including multi-key duplicate reporting and extends permutation proptest coverage.
crates/iddqd/tests/integration/pathological.rs	Adds a pathological flip-key test exercising IdHashMap::from_iter_unique behavior under stale-hash conditions.
CHANGELOG.md	Documents the new constructors and the “report all distinct conflicts” behavior for multi-key maps.

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