refactor: DB snapshot copy specs into descriptors

[francesco-stacks]

Description

This PR refactors the DB snapshot copy logic so each snapshot DB owns a DbSnapshotSpec descriptor. Copy specs now act as the single source of truth for row-copied tables, schema-only tables, table classification, and runtime SQL bind requirements.

• Adds TableCopySource, TableCopySpecs, TableCopyBind, and per-DB DbSnapshotSpec implementations.
• Moves snapshot-only helper reads out of DB impls and into snapshot-specific extension traits.
• Makes schema-only tables explicit in copy specs.
• Replaces table-name based bind matching with explicit bind kinds on the relevant copy specs.
• Updates drift tests to validate the new descriptor-driven structure.

The change was motivated by these suggestions:

• feat: snapshot copy of canonical burnchain DB #7317 (comment)

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 refactors snapshot DB copying so each snapshot DB defines a DbSnapshotSpec descriptor that owns its static table-copy specs (including schema-only tables) and any runtime bind requirements, making the copy-spec list the single source of truth for table classification and copy behavior.

Changes:

• Introduces descriptor-driven snapshot specs (DbSnapshotSpec) plus TableCopySpec/TableCopySource/TableCopyBind and TableCopySpecs helpers to centralize table sets and runtime bind handling.
• Refactors SPV, sortition, index, burnchain, and Nakamoto staging snapshot copy code to use static SQL templates with ?N binds instead of runtime-formatted SQL strings.
• Moves snapshot-only helper reads out of DB impls into snapshot-scoped extension traits and updates snapshot drift/guard tests accordingly.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
stackslib/src/chainstate/stacks/db/snapshot/tests/spv.rs	Updates SPV copy-spec well-formedness guard to use TableCopySpecs and schema-only assertions.
stackslib/src/chainstate/stacks/db/snapshot/tests/sortition.rs	Updates sortition copy-spec guards and adds boundary invariance tests for spec table sets/ordering.
stackslib/src/chainstate/stacks/db/snapshot/tests/index.rs	Simplifies index copy-spec guard to focus on duplicate detection with descriptor-derived tables.
stackslib/src/chainstate/stacks/db/snapshot/tests/burnchain.rs	Updates burnchain copy-spec guard to use TableCopySpecs and clarifies schema-only overrides.
stackslib/src/chainstate/stacks/db/snapshot/tests/blocks.rs	Updates Nakamoto staging copy-spec guard to use TableCopySpecs and schema-only assertions.
stackslib/src/chainstate/stacks/db/snapshot/spv.rs	Introduces SpvDbSnapshotSpec, converts SPV specs to static templates with explicit bind kinds.
stackslib/src/chainstate/stacks/db/snapshot/sortition.rs	Introduces SortitionDbSnapshotSpec, adds snapshot extension trait reads, and refactors boundary-sensitive memo SQL to static templates with binds.
stackslib/src/chainstate/stacks/db/snapshot/index.rs	Introduces IndexDbSnapshotSpec, makes schema-only tables explicit in specs, and refactors reward-cycle filtering to use binds.
stackslib/src/chainstate/stacks/db/snapshot/common.rs	Adds TableCopySource/TableCopyBind/TableCopySpecs and DbSnapshotSpec; updates copy execution to support runtime binds.
stackslib/src/chainstate/stacks/db/snapshot/burnchain.rs	Introduces BurnchainDbSnapshotSpec, moves snapshot-only reads into extension traits, and makes overrides schema-only via specs.
stackslib/src/chainstate/stacks/db/snapshot/blocks.rs	Introduces NakamotoStagingDbSnapshotSpec and refactors staging/microblock copy-spec definitions to static slices.
stackslib/src/chainstate/burn/db/sortdb.rs	Removes snapshot-only helper methods from SortitionDB impl (moved to snapshot extension traits).
stackslib/src/burnchains/db.rs	Removes snapshot-only helper from BurnchainDB impl (moved to snapshot extension traits).

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[federico-stacks]

nit: here and others classify_hint to avoid this string becoming stale, we could derive it from the function itself instead of hardcoding it:

macro_rules! classify_hint {
    ($f:path) => {{
        // Forces `$f` to resolve to a real value (fn item). Wrong name fails at compile time.
        const _: () = { let _ = $f; };
        concat!(stringify!($f), "() in ", file!())
    }};
}

fn classify_hint() -> &'static str {
    fn_hint!(burnchain_copy_specs)  
}

However, I haven't a strong opinion on this. I'm also fine to keep it as-is.