Add actions job log buffer and profiler

[mattdholloway]

Extends the get_job_logs tool and other parts of the MCP server that rely on downloading Actions job log data. The new functionality ensures memory leaks do not occur by using a 'sliding window' buffer to only have 5MB of the log in memory at a time as it reads the entire log. This then allows for a tail step after this that retains the correct amount of lines within the final window before completion.

Closes: https://github.com/github/copilot-agent-services/issues/375

[omgitsads]

Are the content_window_size underscores intentionally, or should they be - instead?

[Copilot]

Pull Request Overview

This PR extends the get_job_logs tool with a sliding window buffer mechanism to prevent memory leaks when processing large Actions job log files. The implementation uses a ring buffer that maintains only the last 5MB (configurable) of log data in memory at any time, significantly reducing memory usage while preserving functionality.

Key changes:

• Added configurable content window size parameter throughout the system
• Implemented ring buffer log processing to handle large files efficiently
• Added performance profiling capabilities to measure memory usage improvements

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
pkg/github/tools.go	Added contentWindowSize parameter to DefaultToolsetGroup and updated GetJobLogs tool instantiation
pkg/github/actions_test.go	Updated test calls to include contentWindowSize parameter and added comprehensive memory usage comparison tests
pkg/github/actions.go	Modified log processing functions to use ring buffer and added profiling integration
pkg/buffer/buffer.go	New ring buffer implementation for efficient log processing with sliding window
internal/profiler/profiler.go	New profiling system for measuring memory usage and performance metrics
internal/ghmcp/server.go	Added ContentWindowSize configuration field and passed it through server initialization
cmd/github-mcp-server/main.go	Added CLI flag for content-window-size configuration
cmd/github-mcp-server/generate_docs.go	Updated calls to include default contentWindowSize value

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.
You can also share your feedback on Copilot code review for a chance to win a $100 gift card. Take the survey.}

[Copilot]

The magic number 1000 should be defined as a named constant to improve maintainability and make the default value explicit throughout the codebase.

Suggested change

	tailLines = 1000
	tailLines = DefaultTailLines

[Copilot]

This condition checks if either value exceeds MaxInt64, but since these are uint64 values, they can legitimately be larger than MaxInt64. The logic should handle the conversion more clearly by checking if the difference itself would overflow int64 bounds.

Suggested change

	return int64(after) - int64(before)
	if after >= before {
	diff := after - before
	if diff > math.MaxInt64 {
	return math.MaxInt64
	}
	return int64(diff)
	}
	diff := before - after
	if diff > math.MaxInt64 {
	return -math.MaxInt64
	}
	return -int64(diff)