Epic: Dead Code Detection

[ajianaz]

Goal

Add cora dead-code command that identifies unreachable symbols — functions, methods, and procedures with zero callers.

Context

Cora already has call_graph (6K+ edges), find_callers(), and trace_path(). Dead code detection is a direct query on existing infrastructure — find symbols with zero incoming CALLS edges, excluding entry points.

Scope

• cora dead-code CLI command
• dead_code MCP tool
• Entry point heuristics (main, new, drop, #[tokio::main], etc.)
• Visibility-aware filtering (pub vs private)
• Test function exclusion (--include-tests)
• Min-line filter (--min-lines N) for tiny stubs
• JSON output (--json)
• Integration with cora scan (report dead code as findings)

Pre-requisite

• Wire up store_kg_edges() — edges table exists but is never populated
• Consider: should dead code use call_graph (legacy) or edges (new) table?

Acceptance Criteria

• cora dead-code lists unreachable functions with file:line
• cora dead-code --json returns structured output
• MCP dead_code tool works in agent context
• Performance: < 10ms on cora-code repo (115 files, 6K edges)

Estimated Effort

2-3 days

[ajianaz]

Sub-issues

• Implement cora dead-code CLI command #427 — Implement cora dead-code CLI command
• Add dead_code MCP tool #428 — Add dead_code MCP tool
• Wire up store_kg_edges() — populate edges table #429 — Wire up store_kg_edges() (blocking)

[ajianaz]

Implemented. Closing as completed — feature verified in codebase.