fix(athena): address 6 council review findings — launcher, schema, filtering, presentation

- Forward temperature and permission through council-launcher to background manager
- Add LaunchInput.temperature and LaunchInput.permission to background-agent types
- Extract session guard with 5-minute timeout to prevent stale council locks
- Make council optional in AthenaOverrideConfigSchema for partial user overrides
- Support member lookup by both name and model ID in filterCouncilMembers
- Add provider/model-id format validation to CouncilMemberSchema
- Fix findings-presenter group header to show finding count instead of first finding's reporter count

src/tools/athena-council/session-guard.ts

@@ -0,0 +1,37 @@
+/** Timeout in ms after which a stale council session lock is automatically released. */
+const COUNCIL_SESSION_TIMEOUT_MS = 5 * 60 * 1000
+
+/** Tracks active council executions per session with timestamps for stale entry cleanup. */
+const activeCouncilSessions = new Map<string, number>()
+
+function purgeStaleEntries(): void {
+  const now = Date.now()
+  for (const [sessionId, startedAt] of activeCouncilSessions) {
+    if (now - startedAt > COUNCIL_SESSION_TIMEOUT_MS) {
+      activeCouncilSessions.delete(sessionId)
+    }
+  }
+}
+
+export function isCouncilRunning(sessionId: string): boolean {
+  purgeStaleEntries()
+  return activeCouncilSessions.has(sessionId)
+}
+
+export function markCouncilRunning(sessionId: string): void {
+  activeCouncilSessions.set(sessionId, Date.now())
+}
+
+export function markCouncilDone(sessionId: string): void {
+  activeCouncilSessions.delete(sessionId)
+}
+
+/** Visible for testing only. */
+export function _resetForTesting(): void {
+  activeCouncilSessions.clear()
+}
+
+/** Visible for testing only. */
+export function _setTimestampForTesting(sessionId: string, timestamp: number): void {
+  activeCouncilSessions.set(sessionId, timestamp)
+}