feat(sql): add configurable WebAssembly scalar UDFs

[ksushant6566]

Adds configurable scalar WebAssembly UDFs to Dozer SQL. With the wasm feature enabled, a .wasm export can be registered in the existing UDF list and called from projections, aggregate expressions and WHERE predicates:

udfs:
  - name: increment
    config: !Wasm
      path: ./math.wasm
      function: addOne

SELECT increment(value) FROM input calls addOne; omitting function uses the SQL UDF name. The generated configuration schema and CLI feature forwarding are included.

The runtime uses Wasmi and infers i32/i64/f32/f64 signatures. It supports checked integer conversion (including Int8), float arguments, SQL NULL propagation, and AssemblyScript env.abort. Modules are compiled during planning and each row gets a fresh instance with fuel, memory and table limits. Invalid argument types are rejected during non-aggregate planning, including SelectionProcessorFactory builds; aggregate argument types are checked against the post-aggregation schema. The included AssemblyScript example has a pinned npm lockfile and a standalone SQL runner.

The supported scalar ABI has one numeric return. Strings/objects through linear memory, reference types, multiple returns and WASI are outside this implementation.

Demo

Watch the approximately 25-second MP4, or download the original terminal recording.

The recording shows a real AssemblyScript build, integer/float results, NULL propagation and an assertion error through Dozer's SQL parser/planner/evaluator. It uses in-memory rows; an ingestion connector is not started. Reproduction instructions are in dozer-tests/wasm_udf/README.md.

Validation

• cargo test --locked -p dozer-sql-expression -p dozer-sql --features wasm --no-default-features: 216 SQL tests, 35 expression unit tests and 5 SQL/WASM integration tests pass; one pre-existing SQL test remains ignored.
• cargo test --locked -p dozer-sql-expression --no-default-features --test wasm_udf: feature-disabled regression passes.
• cargo test -p dozer-types udf_yaml_deserialize: all 4 configuration tests pass.
• cargo clippy --locked -p dozer-sql-expression -p dozer-sql --features wasm --all-targets --no-default-features: succeeds with warnings, including the existing large error types. Changed Rust files pass rustfmt; git diff --check passes.
• cargo check --locked -p dozer-cli --features wasm --no-default-features: passes with Rust 1.78 on macOS arm64. The installed Rust 1.98 hits the unchanged time 0.3.34 E0282 error with or without WASM; no unrelated dependency upgrade is included.
• npm ci and the AssemblyScript build/example run succeed.

Coverage includes numeric boundaries, invalid modules/exports/imports, arity and type errors, NULLs, traps, fuel/memory/table limits, module-state isolation, source-file removal after planning, cloned expressions, nested/aggregate SQL calls, and real WHERE processor insert/update behavior.

AI assistance: implemented and tested with Codex.

Fixes #1653
/claim #1653