Add --section flag and TUI file-group drill-down

[khluu]

Summary

• CLI --section flag: Drill into a group section by name (substring match) to see individual pytest tests, docker steps, or shell commands without launching the TUI. Prints available section names on mismatch.
• TUI file-group view: When expanding a section with pytest tests, an intermediate view now shows test files grouped by filename with total duration and test count. Drilling into a file shows its individual tests.

Motivation

For jobs like "V1 e2e + engine (1 GPU)", bkslow shows a single 2h14m :docker: Running command block. The TUI already supports drilling into sections via AnalyzeSectionLines, but:

• There was no CLI equivalent — you had to launch the TUI
• The TUI jumped straight to ~200 individual pytest tests, making it hard to see which test files are slowest

Examples

# Drill into the docker section from the CLI
bkslow --section "Running command" <job-url>

# Combine with --threshold to find slow tests
bkslow --section "Running command" --threshold 5m <job-url>

# Error case shows available sections
bkslow --section "nonexistent" <job-url>

In the TUI, the new navigation flow is:

Job Detail → File Group (test files) → Individual Tests → Log View

Test plan

• go build ./cmd/bkslow compiles cleanly
• go test ./... all tests pass
• CLI: --section drills into matching section
• CLI: non-matching --section prints available names and errors
• CLI: --threshold works with --section
• TUI: entering a pytest section shows file-group view
• TUI: entering a file group shows individual tests
• TUI: Esc navigates back through file-group correctly

🤖 Generated with Claude Code

[amrmahdi]

should we name this group?

[khluu]

do you mean name the arg to something else? the section names vary job by job so it's hard to pinpoint exactly the section name