feat: enrich echidnabot categories in shared-context bot registry

Add proof-verification, solver-integrity, trust-bridge, axiom-tracking
to Echidnabot BotInfo::standard() categories. Update description to
reflect Tier 1 Verifier role.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Jonathan D.A. Jewell

shared-context/src/bot.rs

@@ -176,12 +176,16 @@ impl BotInfo {
             BotId::Echidnabot => Self {
                 id,
                 name: "Echidnabot".to_string(),
-                description: "Formal mathematical/statistical verification and fuzzing".to_string(),
+                description: "Tier 1 Verifier - formal verification, fuzzing, proof checking".to_string(),
                 version: "0.1.0".to_string(),
                 categories: vec![
                     "verification".to_string(),
                     "fuzzing".to_string(),
                     "proofs".to_string(),
+                    "proof-verification".to_string(),
+                    "solver-integrity".to_string(),
+                    "trust-bridge".to_string(),
+                    "axiom-tracking".to_string(),
                 ],
                 can_fix: false,
                 depends_on: vec![],