fix(athena): force council-first behavior — unconditional prompt + skip keyword injection

The old prompt said 'when requiring multi-model analysis' which let Athena
decide to skip the council and do direct analysis herself. Combined with
keyword-detector injecting [search-mode] telling her to 'launch explore
agents and use Grep directly', Athena never called athena_council.

Two fixes:
1. System prompt now unconditionally requires athena_council as FIRST action
   - Explicitly prohibits Read/Grep/Glob/LSP/call_omo_agent
   - Identity is 'orchestrator, not analyst'
2. keyword-detector skips ALL injections for Athena agent
   - search/analyze/ultrawork modes conflict with council orchestration
   - Same pattern as isPlannerAgent() skip for Prometheus

src/hooks/keyword-detector/hook.ts

@@ -69,6 +69,17 @@ export function createKeywordDetectorHook(
         }
       }
 
+      // Athena is a council orchestrator — skip all keyword injections.
+      // search/analyze modes tell the agent to use explore agents and grep directly,
+      // which conflicts with Athena's job of calling athena_council for council fan-out.
+      if (currentAgent?.toLowerCase() === "athena") {
+        log(`[keyword-detector] Skipping all keywords for Athena (council orchestrator)`, {
+          sessionID: input.sessionID,
+          skippedTypes: detectedKeywords.map((k) => k.type),
+        })
+        return
+      }
+
       if (detectedKeywords.length === 0) {
         return
       }