fix: improve Hyprland 0.55 and MCP schema compatibility

[LikelyLucid]

Summary

• use Hyprland 0.55's Lua focus dispatcher before falling back to the legacy focuswindow dispatcher
• remove Rust-specific unsigned integer format annotations from exported MCP input and output schemas
• add regression coverage for both the Lua expression and exported tool schemas

Motivation

Hyprland 0.55.4 rejects the legacy command used for exact window targeting:

hyprctl dispatch focuswindow address:0x...
')' expected near 'address'

The supported 0.55 form is:

hyprctl dispatch 'hl.dsp.focus({ window = "address:0x..." })'

The Lua-first/legacy-fallback order keeps older Hyprland releases working.

Separately, schemars emits uint, uint8, uint32, and uint64 formats throughout tool schemas. These are not standard JSON Schema formats and produce repeated warnings in MCP clients. The export-boundary sanitizer removes only those format annotations while preserving integer types and numeric constraints.

Validation

Manually validated on Hyprland 0.55.4, including cross-workspace exact focus.

cargo fmt --all -- --check
cargo check --locked --all-targets
cargo clippy --locked --all-targets -- -D warnings
cargo test --locked --no-fail-fast
python3 scripts/mcp_safety_check.py

Results: 134 library tests passed; MCP safety check passed for all 18 tools. The schema regression test confirms no unsupported unsigned formats remain in either input or output schemas.

[gemini-code-assist]

Code Review

This pull request introduces schema sanitization to remove unsupported unsigned integer formats from exported tool schemas in src/server.rs, along with corresponding unit tests. It also updates window activation in src/windowing/backends/hyprland.rs to try a new Lua-based focus dispatcher before falling back to the legacy command. Feedback suggests simplifying the recursion logic in sanitize_unsigned_integer_formats by matching directly on the serde_json::Value enum to make the traversal cleaner and more robust.

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[gemini-code-assist]

The recursion logic in sanitize_unsigned_integer_formats can be simplified and made more robust by matching directly on the serde_json::Value enum, similar to how it is done in the test helper collect_unsigned_integer_formats. This avoids the nested match inside the loop and ensures that any nested array-of-arrays or other structures are correctly traversed.

fn sanitize_unsigned_integer_formats(value: &mut serde_json::Value) {
    match value {
        serde_json::Value::Object(object) => {
            let has_unsigned_format = matches!(
                object.get("format").and_then(serde_json::Value::as_str),
                Some("uint" | "uint8" | "uint16" | "uint32" | "uint64" | "usize")
            );
            if has_unsigned_format {
                object.remove("format");
            }
            for nested in object.values_mut() {
                sanitize_unsigned_integer_formats(nested);
            }
        }
        serde_json::Value::Array(items) => {
            for item in items {
                sanitize_unsigned_integer_formats(item);
            }
        }
        _ => {}
    }
}

[avifenesh]

Thanks @LikelyLucid — this is a great contribution. The Lua-first/legacy-fallback focus order is exactly the right compatibility shape, and stripping the non-standard schemars uint formats at the export boundary (with regression coverage) cleans up a real annoyance for MCP clients. CI is fully green, merging. This will go out in the next release shortly.