fix: include empty properties in get_me schema for OpenAI compatibility

[SamMorrowDrums]

Closes #1553

Summary

OpenAI strict mode requires the properties field to be present in object schemas, even when empty. The get_me tool has no input parameters, so its schema was {"type": "object"} without a properties field.

Problem

The jsonschema library's Schema struct uses omitempty JSON tags, causing empty maps to be omitted during JSON serialization. Even when setting Properties: map[string]*jsonschema.Schema{}, the output remains {"type": "object"}.

Error from OpenAI:

Error code: 400 - {'error': {'message': "Invalid schema for function 'get_me': In context=(), object schema missing properties.", 'type': 'invalid_request_error', 'param': 'tools[13].function.parameters', 'code': 'invalid_function_parameters'}}

Solution

Use json.RawMessage to bypass the library's serialization and explicitly include "properties": {} in the output:

InputSchema: json.RawMessage(`{"type":"object","properties":{}}`)

This ensures OpenAI strict mode compatibility while maintaining the same logical schema.

Testing

• ✅ script/lint - 0 issues
• ✅ script/test - all tests pass
• ✅ Toolsnap updated to reflect new schema with "properties": {}

Fixes #1548

[Copilot]

Pull request overview

This PR fixes an OpenAI strict mode compatibility issue where the get_me tool's input schema lacked an explicit properties field. OpenAI's strict mode requires object schemas to include the properties field even when empty, but the jsonschema library omits empty maps during serialization due to omitempty tags.

Key Changes

• Modified get_me tool to use json.RawMessage for explicit schema control
• Updated toolsnap to reflect the new schema with empty properties object

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pkg/github/context_tools.go	Changed InputSchema from &jsonschema.Schema{Type: "object"} to json.RawMessage with explicit "properties": {} to ensure OpenAI strict mode compatibility
pkg/github/toolsnaps/get_me.snap	Updated snapshot to reflect the new schema format including the empty properties field