bug: GNNService incorrectly passes config.layers to RuvectorLayer constructor

[ruvnet]

Issue Summary

Upstream Issue: ruvnet/RuVector#216

GNNService in agentic-flow incorrectly passes config.layers instead of config.heads to the RuvectorLayer constructor, causing dimension mismatch errors.

Problem

// Current (WRONG)
const layer = new RuvectorLayer(config.layers); // Should be config.heads

// Example: config = { heads: 8, layers: 3 }
// Result: Tries to create layer with 128 % 3 ≠ 0 (invalid)

Impact

• Severity: Medium (GNN routing fails to initialize)
• Affected: GNNService, gnn-tools.ts (6 MCP tools)
• Workaround: Use correct head count in config
• Fix Location: agentic-flow/src/services/gnn-router-service.ts

Root Cause

Two-part issue:

1. agentic-flow (us): Passes wrong config parameter
2. ruvector (upstream): Uses panic instead of Result (fatal in FFI)

Temporary Fix (Our Side)

```typescript
// In GNNService constructor

• const layer = new RuvectorLayer(config.layers);

• const layer = new RuvectorLayer(config.heads);
  ```

Upstream Fix Needed

@ruvector/gnn needs to return Result instead of panic:
```rust
// Current
pub fn new(num_heads: usize) -> Self {
assert!(EMBEDDING_DIM % num_heads == 0); // PANICS

// Proposed
pub fn new(num_heads: usize) -> Result<Self, GnnError> {
if EMBEDDING_DIM % num_heads != 0 {
return Err(GnnError::InvalidHeads { ... });
}
Ok(Self { ... })
}
```

Action Items

• Fix GNNService parameter (agentic-flow)
• Update tests to use correct config
• Wait for upstream Result-based constructor
• Update to @ruvector/gnn with proper error handling

Files to Update

1. `agentic-flow/src/services/gnn-router-service.ts` - Fix constructor call
2. `tests/integration/gnn-activation.test.ts` - Update test configs
3. `agentic-flow/src/mcp/fastmcp/tools/gnn-tools.ts` - Add config validation

Related

• Upstream: fix(ruvector-gnn): RuvectorLayer constructor panics instead of returning Result RuVector#216
• ADR-065: P1 Intelligent Agents (GNN routing)
• Test: `tests/integration/gnn-activation.test.ts`

Priority

P1 - Blocks GNN routing functionality, but has workaround.