mandatory pre-plan flow: goal → research → plan → APPROVE → execute

SOUL.md: mandatory 6-step task flow at TOP of file, unmissable.
Agent MUST: set_goal → pre-plan (research only) → propose_plan → STOP
and wait for approval → execute (auto-run under plan window).

Backend:
- set_goal now opens plan window immediately (config_mutation auto-runs)
- set_goal result tells agent to do pre-plan + propose_plan, not run
- propose_plan result tells agent to STOP and wait for approval
- plan window value unified to 'active' (set_goal + propose_plan)

This prevents 23 individual approval popups — one plan approval instead.

internal/mcp/server.go

@@ -1440,7 +1440,7 @@ func planWindowActive(ctx context.Context, pool *db.Pool, sessionID string) bool
 	err := pool.QueryRow(ctx,
 		"SELECT value FROM autonomy_settings WHERE key = $1",
 		"nomos:plan:"+sessionID).Scan(&val)
-	return err == nil && (val == "proposed" || val == "active")
+	return err == nil && val == "active"
 }
 
 // assentWindowActive checks whether the operator has recently approved a plan