Add g16.verify Groth16 verifier builtin

[elldeeone]

Summary

Adds g16.verify(...) as a SilverScript builtin for verifying Groth16 proofs via the Rusty Kaspa ZK precompile.

The builtin signature is:

g16.verify(byte[] verifyingKey, byte[] proof, byte[32] ...publicInputs): bool

This PR includes:

• parser/AST/formatter support for qualified builtin call targets such as g16.verify
• compiler lowering to OpZkPrecompile with ZkTag::Groth16
• static validation for byte[] verifying key/proof arguments and byte[32] public inputs
• bool return typing so g16.verify(...) can be assigned/required like other boolean builtins
• docs, syntax highlighting, and generated tree-sitter parser updates
• runtime coverage using a valid Groth16 fixture plus a tampered-input failure case
• debugger shadow-script support for post-Toccata-sized runtime params, so large byte[] values such as verifying keys/proofs can be inspected during expression evaluation

Notes

The debugger CLI still has pre-existing v2.0.1 migration debt around v1 transaction compute_commit construction (SigopCount vs ComputeBudget). I left that transaction-building path unchanged here because it predates this feature and is separate from the compiler builtin, but I can include it in this PR if maintainers would prefer to handle that post-Toccata debugger cleanup together.

Tests

cargo test -p silverscript-lang --test compiler_tests g16_verify
cargo test -p debugger-session
cargo test -p silverscript-lang --test examples_tests g16_verify
cargo test -p silverscript-lang --test parser_tests
cargo test -p silverscript-lang --test ast_format_tests
git diff --check upstream/master...HEAD

[elldeeone]

I missed that #137 was already the ZK base.

I’m going to move this to draft for now and restack it on top of #137 once that lands, so g16.verify can reuse the qualified builtin/parser/compiler shape from the R0 support work instead of duplicating that machinery.