fix(nomos): sessions blocked on an execution approval now show "Needs input" and never idle-close

A config_mutation/destructive run() queued for approval never touched
agent_sessions.status — only ask_operator did that, setting
awaiting_input. So a task blocked on an execution approval was
indistinguishable from one still genuinely working: the frontend's
"Needs input" bucket only checks status===awaiting_input (never lit
up for these), and the idle-sweep safety net only excludes
awaiting_input from its stale-task query, so after ~30 minutes idle
it would nudge the agent and then auto-close the task with
outcome=partial while the approval was still sitting there undecided.

classifyAndGate now flips the session into awaiting_input the moment
an execution is queued (internal/mcp/server.go), and DecideApproval
flips it back to executing once the approval is approved, denied, or
revoked (internal/httpapi/approvals.go) — mirroring askOperator /
answerQuestion's existing pattern for session_questions. Both emit
task.status so the board updates live.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/httpapi/approvals.go

@@ -229,6 +229,33 @@ func (s *Server) DecideApproval(ctx context.Context, req gen.DecideApprovalReque
 		_, _ = tx.Exec(ctx, `UPDATE executions SET status = $2, completed_at = now() WHERE approval_id = $1 AND status = 'pending_approval'`, id, status)
 	}
 
+	// If this execution belongs to a nomos session, flip it out of
+	// awaiting_input — the counterpart to classifyAndGate flipping it IN
+	// the moment the approval was created (internal/mcp/server.go's
+	// markSessionAwaitingApproval). Runs for all three decisions (approve/
+	// deny/revoke): each one is an operator answer to "what do I do about
+	// this?", same as answerQuestion's unconditional resume-to-executing
+	// (cmd/nomos/store.go) for a session_questions answer.
+	var awaitingSessionID string
+	_ = tx.QueryRow(ctx, `
+		SELECT pe.session_id FROM nomos_plan_executions pe
+		JOIN executions ex ON ex.entity_id = pe.execution_id
+		WHERE ex.approval_id = $1
+		LIMIT 1`, id).Scan(&awaitingSessionID)
+	if awaitingSessionID != "" {
+		if rtag, rerr := tx.Exec(ctx, `
+			UPDATE agent_sessions SET status = 'executing', last_active_at = now()
+			WHERE id = $1 AND status = 'awaiting_input'`, awaitingSessionID); rerr == nil && rtag.RowsAffected() > 0 {
+			var taskEntID *uuid.UUID
+			var e uuid.UUID
+			if qerr := tx.QueryRow(ctx, `SELECT entity_id FROM agent_sessions WHERE id = $1`, awaitingSessionID).Scan(&e); qerr == nil && e != uuid.Nil {
+				taskEntID = &e
+			}
+			_ = observability.Event(ctx, q, "task.status", taskEntID, "info", "api", awaitingSessionID,
+				map[string]any{"status": "executing", "reason": "approval_decided", "decision": status})
+		}
+	}
+
 	if err := tx.Commit(ctx); err != nil {
 		return nil, err
 	}