Add auto gate handler for hexagon nodes

[gabehamilton]

Summary

• Adds AutoGateHandler for hexagon nodes with auto_policy attribute, enabling automated review loops without human interaction
• Routes hexagon nodes with auto_policy to auto.gate handler instead of wait.human
• Supports findings_empty policy (pass when findings_count is 0) and max_iterations cap (force pass when exceeded)

Test plan

• Unit tests for findings edge routing on first iteration
• Unit tests for max_iterations force-pass
• Unit tests for findings_empty with zero count
• Unit tests for iteration counter incrementing
• Registry resolution tests for hexagon with/without auto_policy

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request introduces the AutoGateHandler, a new node handler for automatic gate nodes in the graph. It supports iteration limits and policy-based routing (e.g., findings_empty). The feedback identifies several critical issues: the parsing of max_iterations is fragile and doesn't handle string values from DOT files; the logic for falling back when specific edges (like 'pass' or 'findings') are missing results in empty suggested_next_ids, which would prematurely terminate the graph execution; and the edge label matching is overly permissive, potentially leading to incorrect routing if labels contain substrings like 'bypass'.

[gemini-code-assist]

The current parsing of max_iterations only handles integer attributes. If the attribute is provided as a string in the DOT file (e.g., max_iterations="10"), as_i64() will return None, causing it to default to 5. Additionally, using as usize on a potentially negative i64 can lead to unexpected behavior. It's safer to use to_string_value().parse() which handles both numeric and string representations robustly.

Suggested change

	let max_iterations = node
	.attrs
	.get("max_iterations")
	.and_then(|v| v.as_i64())
	.unwrap_or(5) as usize;
	let max_iterations = node
	.attrs
	.get("max_iterations")
	.map(|v| v.to_string_value().parse::<usize>().unwrap_or(5))
	.unwrap_or(5);

[gemini-code-assist]

The comment indicates a fallback to the first edge if no specific 'pass' edge is found, but the implementation returns a NodeOutcome with an empty suggested_next_ids list. This will cause the graph execution to stop unexpectedly at this node. The fallback should explicitly select the first available edge to maintain graph flow.

            let edge = edges.first().ok_or_else(|| AttractorError::Runtime("auto gate: no outgoing edges".to_string()))?;
            return Ok(NodeOutcome {
                status: NodeStatus::Success,
                preferred_label: Some(edge.attrs.get_str("label").unwrap_or("").to_string()),
                suggested_next_ids: vec![edge.to.clone()],
                context_updates: updates,
                notes: Some(format!("{reason} (no pass edge found, falling back to first edge)")),
                ..Default::default()
            });

[gemini-code-assist]

When no findings edge is found, the handler should still provide a next node ID to continue execution. Currently, it returns an empty suggested_next_ids list, which effectively terminates the pipeline. It should fall back to the pass_edge or the first available edge.

            let edge = pass_edge.or_else(|| edges.first()).ok_or_else(|| AttractorError::Runtime("auto gate: no outgoing edges".to_string()))?;
            Ok(NodeOutcome {
                status: NodeStatus::Success,
                preferred_label: Some(edge.attrs.get_str("label").unwrap_or("").to_string()),
                suggested_next_ids: vec![edge.to.clone()],
                context_updates: updates,
                notes: Some("auto gate: no findings edge, defaulting to pass".to_string()),
                ..Default::default()
            })

[gemini-code-assist]

Using contains for label matching is too permissive and can lead to incorrect routing. For example, label_is_pass would match a label like "bypass", and label_is_findings would match "no findings". It is better to check for the specific [P] / [F] prefix or perform exact word matching to ensure the correct edge is selected.

Suggested change

	fn label_is_pass(label: &str) -> bool {
	let lower = label.to_ascii_lowercase();
	lower.contains("[p]") || lower.contains("pass")
	}
	fn label_is_findings(label: &str) -> bool {
	let lower = label.to_ascii_lowercase();
	lower.contains("[f]") || lower.contains("findings") || lower.contains("finding")
	}
	fn label_is_pass(label: &str) -> bool {
	let lower = label.to_ascii_lowercase();
	lower.contains("[p]") || lower == "pass" || lower.starts_with("pass ")
	}
	fn label_is_findings(label: &str) -> bool {
	let lower = label.to_ascii_lowercase();
	lower.contains("[f]") || lower.starts_with("finding")
	}

[gabehamilton]

@claude address pr review comments