fix: clarity tuple field validation

[francesco-stacks]

Description

Fixes a bug in from-consensus-buff? that currently makes it possible to create a clarity tuple with duplicate keys of the same type. When such a buffer is deserialized, it's converted into a tuple that violates its own declared type.

The fix is gated behind 4.1. Now a duplicate will cause from-consensus-buff? to return None.

• TupleData::from_data_typed now derives the actual type via from_data (which rejects duplicates) and requires the value to contain exactly the declared field set before caching the expected signature.
• Deserialization threads a strict_tuple_fields flag, which is controlled based on the epoch.
• from-consensus-buff? and the DB read path (RollbackWrapper::get_value) now both use the epoch-aware entry.

Applicable issues

• fixes #

Additional info (benefits, drawbacks, caveats)

Checklist

• Test coverage for new or modified code paths
• For new Clarity features or consensus changes, add property tests (see docs/property-testing.md)
• Changelog fragment(s) or "no changelog" label added (see changelog.d/README.md)
• Required documentation changes (e.g., rpc/openapi.yaml for RPC endpoints, event-dispatcher.md for new events)
• New clarity functions have corresponding PR in clarity-benchmarking repo

[Copilot]

Pull request overview

This PR fixes an epoch-gated (Epoch 4.1+) type-soundness issue in Clarity typed-tuple deserialization, where consensus buffer deserialization could accept duplicate tuple keys and produce tuples that violate their declared type. The change introduces epoch-aware deserialization entry points and threads a strict tuple-field enforcement flag so from-consensus-buff? and DB reads reject malformed typed tuples starting in Epoch 4.1 while preserving legacy behavior in earlier epochs.

Changes:

• Add Epoch 4.1 gate (enforces_exact_typed_tuple_field_set) and plumb it through epoch-aware deserialization APIs.
• Enforce strict typed-tuple field rules (no duplicates; exact declared field set after sanitization) during typed tuple construction/deserialization when the epoch gate is active.
• Add targeted tests covering from-consensus-buff?, typed tuple deserialization behavior across epochs, and the DB read path gating; add a changelog fragment.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
stackslib/src/chainstate/tests/runtime_analysis_tests.rs	Updates test commentary to reference the new epoch-aware exact-deserialization entry point.
stacks-common/src/types/mod.rs	Introduces an Epoch 4.1+ helper to gate strict typed-tuple field-set enforcement.
clarity/src/vm/tests/conversions.rs	Adds an epoch-gated regression test ensuring from-consensus-buff? rejects duplicate typed-tuple fields at Epoch 4.1+.
clarity/src/vm/functions/conversions.rs	Switches from-consensus-buff? to epoch-aware exact deserialization so enforcement is driven by execution epoch.
clarity/src/vm/database/key_value_wrapper.rs	Switches DB value deserialization to an epoch-aware entry point.
clarity/src/vm/database/clarity_db.rs	Adds a regression test ensuring DB reads reject malformed typed tuples at Epoch 4.1+.
clarity-types/src/types/serialization.rs	Threads strict_tuple_fields through the deserializer and adds epoch-aware deserialization APIs (bytes/hex, exact + non-exact).
clarity-types/src/types/mod.rs	Extends TupleData::from_data_typed with a strict option to reject duplicates and enforce exact field sets.
clarity-types/src/tests/types/serialization.rs	Adds comprehensive epoch-gated tests for duplicate/missing/extra tuple field handling (including nesting + trailing bytes).
clarity-types/src/tests/types/mod.rs	Updates and adds unit tests for strict TupleData::from_data_typed behavior.
changelog.d/typed-tuple-deserialization.fixed	Documents the Epoch 4.1 behavior change for from-consensus-buff?.

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[brice-stacks]

lgtm! just one performance nit.

[brice-stacks]

lgtm