fix(wasm): use typed WASM schema as advertised schema when available

[anthhub]

Summary

When a WASM tool exports a typed schema with properties, use it as the advertised schema instead of always falling back to permissive {}. This lets the LLM see the correct parameter requirements and avoids repeated calls with empty params.

• In wrapper.rs: WasmToolSchemas::new() now checks if the extracted schema has typed properties and uses it as the advertised schema
• In loader.rs: updated the misleading "missing parameters" warning to account for WASM-exported schemas

Fixes #1303

Test plan

• Unit test verifying typed schema propagation
• cargo check / cargo check --no-default-features --features libsql / cargo check --all-features
• cargo clippy --all --tests — zero warnings

[gemini-code-assist]

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[zmanian]

Approve. Fallback logic is correct: required/enum props -> typed props -> permissive {}. The schema_is_typed_property helper is comprehensive. Good test coverage. Minor suggestion: add a test for mixed typed/untyped properties in the fallback path.