refactor: reduce complexity of main in src/main.rs

[github-actions]

What was complex

main() in src/main.rs was 224 lines with a heuristic complexity score of 44 — the highest in the codebase. The root cause was the Execute command arm, which packed ~120 lines of deeply-nested logic directly inside a match arm:

• reading and parsing the source markdown
• building the allowed-repositories map (an explicit for + if let loop)
• constructing ExecutionContext field-by-field with multiple if let branches
• loading OTel agent stats with nested if otel_path.exists() / match / if let
• executing safe outputs
• processing cache-memory with a further if let Some(cm) / if cm.is_enabled() nest
• computing and printing the summary
• std::process::exit with two separate exit-code branches

The top-level if let Some(command) = args.command { match command { ... } } else { ... } also added unnecessary nesting depth.

What changed

Four focused helper functions extracted:

Helper	Responsibility
run_compile	Handles --skip-integrity / --debug-pipeline warnings and dispatch to compile_pipeline / compile_all_pipelines
run_execute	Thin orchestrator: parse → context → run → memory → summary → exit
build_execution_context	Constructs ExecutionContext from FrontMatter + CLI overrides + OTel stats
process_cache_memory	Checks cache-memory tool config and runs memory artifact processing
print_execution_summary	Formats and prints the final success/warning/failure counts

The top-level if let ... else was replaced with let Some(command) = args.command else { ... } + an unconditional match, removing one level of nesting.

Before / After

Metric	Before	After
main lines	224	~60
Heuristic complexity score	44	~12
Clippy cognitive-complexity warnings	0 (threshold ≥ 25)	0

Verification

• cargo build — clean (0 errors, 0 new warnings)
• cargo test — all tests pass
• cargo clippy --all-targets --all-features — no new warnings
• Clippy cognitive-complexity lint — no warnings at default threshold

Generated by Cyclomatic Complexity Reducer · ● 2.6M · ◷